Note: Descriptions are shown in the official language in which they were submitted.
COMBUSTIBLE GAS SENSING ELEMENT WITH CANTILEVER SUPPORT
CLAIM TO PRIORITY
[0001] This application claims the benefit of the following applications:
United States
Serial No. 62/384,798, filed September 8, 2016 (ISCI-0025-P01); United States
Serial No.
62/409,706, filed October 18, 2016 (ISCI-0034-P01); United States Serial No.
62/397,587,
filed September 21, 2016 (ISCI-0035-P01); United States Serial No. 62/384,803,
filed
September 8, 2016 (ISCI-0036-P01); United States Serial No. 62/463,230, filed
February 24,
2017 (ISCI-0038-P01); United States Serial No. 15/491,311, filed April 19,
2017 (ISCI-0039-
U01); and United States Serial No. 62/385,688, filed September 9, 2016 (ISCI-
0037-P01).
[0002] This application is also related to the following U.S. patents and
patent applications
US Patent No. 9,000,910 filed on June 24, 2011 (ISCI-0020-U01), US Patent No.
9,575,043
filed April 1, 2015 (ISCI-0020-U01-001), US Patent Application Serial No.
15/376,823, filed
December 13, 2016 (ISCI-0020-U01-001-001), US Patent No. 6,338,266 filed April
5, 2000
(ISCI-0005-U01), US Patent No. 6,435,003 filed November 8, 2001 (ISCI-0005-U01-
V01),
US Patent No. 6,888,467 filed December 10, 2002 (ISCI-0014-U01), US Patent No.
6,742,382 filed December 24, 2002 (ISCI-0015-U01), US Patent No. 6,442,639
filed April
19, 2000 (ISCI-0006-U01), US Patent No. 7,007,542 filed June 16, 2003 (ISCI-
0009-U01-
V01), and U.S. Patent Application Serial No. 2016/0209386, entitled MODULAR
GAS
MONITORING SYSTEM and filed on January 15, 2016 (ISCI-0023-U01).
BACKGROUND
[0003] Field:
[0004] The invention relates to combustible gas sensors, and more particularly
to a
combustible gas sensor with improved mechanical stability.
SUMMARY
[0005] In an aspect, a tangible article of manufacture having instructions
stored thereon
that, when executed, causes a machine to perform operations for tracking an
operator and
operator status using a safety device, the operations comprising: programming
a plurality of
NFC tags with assignment information, wherein the assignment information is at
least one of
a location assignment for NFC tags being placed at particular locations and an
instrument
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operator assignment for tags distributed to multi-gas detection instrument
operators; receiving
temporary assignment information at the safety device when an NFC radio of the
safety
device is brought in proximity to at least one of the plurality of NFC tags;
and tagging safety
device data with the temporary assignment information. In this aspect and
others disclosed
herein, the programming of the plurality of NFC tags is not required. In fact,
pre-
programmed NFC tags may be purchase for use in the systems and methods
disclosed herein.
The operations further include storing the tagged safety device data in a
safety device data
log. The operations further include wirelessly transmitting the tagged safety
device data to at
least one of a cloud-based or other remote log and a second device. The
operations further
include removing the temporary assignment by bringing the safety device into
proximity to
the at least one NFC tag again. The safety device is a multi-gas detection
instrument, a gas
detection instrument, or at least one of a respirator, a harness, a lighting
device, a fall arrest
device, a thermal detector, a flame detector, and a chemical, biological,
radiological, nuclear,
and explosives (CBRNE) detector.
[0006] In an aspect, a tangible article of manufacture having instructions
stored thereon
that, when executed, causes a machine to perform operations for tracking an
operator and
operator status using a safety device, the operations comprising: programming
a plurality of
NFC tags with assignment information, wherein the assignment information is at
least one of
a location assignment for NFC tags being placed at particular locations and an
instrument
operator assignment for tags distributed to safety device operators; receiving
assignment
information at the safety device when an NFC radio of the safety device is
brought in
proximity to at least one of the plurality of NFC tags; and triggering one or
more of an alarm
and a message upon detection of a safety event, wherein the trigger is
filtered by the
temporary assignment information. The assignment tags for identifying
individuals are
programmed with information including one or more of a name, a size, a weight,
a typical
work location, a job function, a typical instrument used, a pre-existing
concern, a language
known, a prior alarm, a prior gas event, a prior safety event, and a prior
message. The
assignment tags for identifying locations are programmed with information
including one or
more of a location within a space, a GPS location, an equipment at the
location, a fuel source
at the location, a known hazard at the location, a typical gas concentration
for the location, an
environmental condition for the location, a recent gas event, a recent man
down alarm, a
recent alarm, and a recent message. Triggering further comprises applying a
filter based on
the assignment tag's programmed information. The safety device is at least one
of a multi-gas
detection instrument, a gas detection instrument, a respirator, a harness, a
lighting device, a
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fall arrest device, a thermal detector, a flame detector, and a chemical,
biological,
radiological, nuclear, and explosives (CBRNE) detector. The safety event is a
gas event.
[0007] In an aspect, an industrial safety monitoring system includes a
personal NFC tag
assigned to a worker, wherein the tag assigned to the worker comprises
information of the
identity of the worker; a plurality of location NFC tags assigned to
locations, each location
tag placed in a location comprising information of the location in which the
location tag is
placed; at least one portable environmental sensing device detecting data of
an environmental
parameter, the at least one portable environmental sensing device configured
to (i) read the
personal NFC tag and to transmit the information of the identity of the worker
using the
sensing device, and (ii) read at least one of the plurality of location NFC
tags and to transmit
the information of the location of a location tag read by the at least one
portable
environmental sensing device; and at least one processor in communication with
the at least
one portable environmental sensing device and receiving from the at least one
portable
environmental sensing device (i) detected data of an environmental parameter,
(ii) the
information of the identity of the worker using the at least one portable
environmental
sensing device, and (iii) information of the location of a location tag read
by the at least one
portable environmental sensing device, wherein the at least one processor is
programmed to
determine an environmental parameter of the worker using the sensing device
and the
location of the determined environmental parameter. The system further
includes a memory
in communication with the at least one portable environmental sensing device
that stores the
detected data and the information in a portable environmental sensing device
data log. The
system further includes a wireless transmitter that transmits the detected
data and the
information to at least one of a cloud-based or other remote log and a second
portable
environmental sensing device. The assignment tags for identifying workers are
programmed
with information including one or more of a name, a size, a weight, a typical
work location, a
job function, a typical instrument used, a pre-existing concern, a language
known, a prior
alarm, a prior gas event, a prior safety event, and a prior message. The
assignment tags for
identifying locations are programmed with information including one or more of
a location
within a space, a UPS location, an equipment at the location, a fuel source at
the location, a
known hazard at the location, a typical gas concentration for the location, an
environmental
condition for the location, a recent gas event, a recent man down alarm, a
recent alarm, and a
recent message. The at least one portable environmental sensing device is at
least one of a
multi-gas detection instrument, a gas detection instrument, a respirator, a
harness, a lighting
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device, a fall arrest device, a thermal detector, a flame detector, and a
chemical, biological,
radiological, nuclear, and explosives (CBRNE) detector.
[0008] In an aspect, a tangible article of manufacture having instructions
stored thereon
that, when executed, causes a machine to perform operations for tracking an
operator and
operator status using a safety device, the operations comprising: programming
a plurality of
NFC tags with assignment information, wherein the assignment information is at
least one of
a location assignment for NFC tags being placed at particular locations and an
instrument
operator assignment for tags distributed to safety device operators; receiving
assignment
information at the safety device when an NFC radio of the safety device is
brought in
proximity to at least one of the plurality of NFC tags; and triggering an
activation of a
function of the safety device based on the temporary assignment information.
[0009] In an aspect, A tangible article of manufacture having instructions
stored thereon
that, when executed, causes a machine to perform operations for tracking an
operator and
operator status using a safety device, the operations comprising: programming
a plurality of
NFC tags with assignment information, wherein the assignment information is at
least one of
a location assignment for NFC tags being placed at particular locations and an
instrument
operator assignment for tags distributed to safety device operators; receiving
assignment
information at the safety device when an NFC radio of the safety device is
brought in
proximity to at least one of the plurality of NFC tags; and triggering a
modification of a
setting of the safety device based on the temporary assignment information.
[0010] In an aspect, a tangible article of manufacture having instructions
stored thereon
that, when executed, causes a machine to perform operations for tracking an
operator and
operator status using a safety device, the operations comprising: programming
a plurality of
NFC tags with assignment information, wherein the assignment information is at
least one of
a location assignment for NFC tags being placed at particular locations and an
instrument
operator assignment for tags distributed to safety device operators; receiving
assignment
information at the safety device when an NFC radio of the safety device is
brought in
proximity to at least one of the plurality of NFC tags; triggering one or more
of an alarm and
a message upon detection of a safety event, wherein the triggered alarm or
message is filtered
by the temporary assignment information; and communicating the triggered alarm
or message
to at least one other safety device in a mesh network with features as
described herein for
presentation on the second safety device. The assignment tags for identifying
individuals are
programmed with information including one or more of a name, a size, a weight,
a typical
work location, a job function, a typical instrument used, a pre-existing
concern, a language
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known, a prior alarm, a prior gas event, a prior safety event, and a prior
message. The
assignment tags for identifying locations are programmed with information
including one or
more of a location within a space, a GPS location, an equipment at the
location, a fuel source
at the location, a known hazard at the location, a typical gas concentration
for the location, an
environmental condition for the location, a recent gas event, a recent man
down alarm, a
recent alarm, and a recent message. Triggering further comprises applying a
filter based on
the assignment tag's programmed information. The safety device is at least one
of a multi-gas
detection instrument and a gas detection instrument. The safety device is at
least one of a
respirator, a harness, a lighting device, a fall arrest device, a thermal
detector, a flame
detector, and a chemical, biological, radiological, nuclear, and explosives
(CBRNE) detector.
The safety event is a gas event.
[0011] In an aspect, a tangible article of manufacture having instructions
stored thereon
that, when executed, causes a machine to perform operations for tracking an
operator and
operator status using a safety device, the operations comprising: programming
a plurality of
NFC tags with assignment information, wherein the assignment information is at
least one of
a location assignment for NFC tags being placed at particular locations and an
instrument
operator assignment for tags distributed to safety device operators; receiving
assignment
information at the safety device when an NFC radio of the safety device is
brought in
proximity to at least one of the plurality of NFC tags; triggering a
modification of a setting of
the safety device based on the temporary assignment information; and
communicating the
modified setting to at least one other safety device in a mesh network with
features as
described herein for modification of a setting of the second safety device.
[0012] In an aspect, an alerting system includes a safety device comprising a
GPS system;
and an interface configured to: transmit the location of the safety device
based on data from
the GPS system to a remote server; receive alert information from the remote
server in
response to the remote server determining the location of the safety device
corresponds to a
hazardous location, wherein the remote server determines the hazardous
location based on a
condition detected from one or more of the safety device, a second safety
device in an area
within a pre-defined distance from the safety device, an area monitor, and
third party data;
and communicate the alert information to one or more devices in a mesh network
with
features as described herein joined by the safety device. The interface is a
component of the
safety device, a network gateway, or a smart phone.
[0013] In an aspect, an alerting system includes a safety device configured to
read at least
one of a plurality of location NFC tags comprising information regarding the
location in
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which it is placed; and an interface configured to: transmit the location of
the safety device
based on the information from the location NFC tag to a remote server; and
receive alert
information from the remote server in response to the remote server
determining the location
of the safety device corresponds to a hazardous location, wherein the remote
server
determines the hazardous location based on a condition detected from one or
more of the
safety device, a second safety device in the location, an area monitor in the
location, and third
party data related to the location. The interface is a component of the safety
device, a
network gateway, or a smart phone. The interface is further configured to
communicate the
alert information to one or more devices in a mesh network joined by the
safety device.
[0014] In an aspect, a computer-implemented method for providing real time
locating and
gas exposure monitoring includes receiving, by a computer processor, a first
gas reading and
a first location from a first device; receiving, by the computer processor, a
second location
from a second device; and transmitting one or more of an alert and the gas
reading to the
second device when the second location is within a predetermined distance from
the first
location and the gas reading exceeds a threshold, wherein the second device
relays the alert
and/or the gas reading to at least one peer device in a mesh network with
features as
described herein joined by the second device.
[0015] In an aspect, a computer-implemented method for providing real time
locating and
gas exposure monitoring includes receiving, by a computer processor, a first
gas reading and
a first location from a first device, wherein the first location is read from
a location NFC tag
in the location by the first device; receiving, by the computer processor, a
second location
from a second device; and transmitting one or more of an alert and the gas
reading to the
second device when the second location is within a predetermined distance from
the first
location and the gas reading exceeds a threshold. The second device relays the
alert and/or
the gas reading to at least one peer device in a mesh network with features as
described
herein joined by the second device.
[0016] In an aspect, a computer-implemented method for providing real time
locating and
gas exposure monitoring includes receiving, by a computer processor, a first
safety event and
a first location from a first device; receiving, by the computer processor, a
second location
from a second device; and transmitting an alert and the safety event to the
second device
when the second location is within a predetermined distance from the first
location, wherein
the second device relays the alert and/or the gas reading to at least one peer
device in a mesh
network with features as described herein joined by the second device.
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[0017] In an aspect, a computer-implemented method for providing real time
locating and
gas exposure monitoring includes receiving, by a computer processor, a first
safety event and
a first location from a first device, wherein the first location is read from
a location NFC tag
in the location by the first device; receiving, by the computer processor, a
second location
from a second device; and transmitting an alert and the safety event to the
second device
when the second location is within a predetermined distance from the first
location. The
second device relays the alert and/or the gas reading to at least one peer
device in a mesh
network with features as described herein joined by the second device.
[0018] In an aspect, a system includes a plurality of portable environmental
sensing devices
in a work area adapted to communicate with one another in a mesh network with
features as
described herein; and a communications facility to transmit data from at least
one of the
plurality of portable environmental sensing devices to a remote computer, the
remote
computer configured to monitor at least one of a hazardous condition and an
activation of a
panic button in the work area based on data from the at least one of the
plurality of portable
environmental sensing devices, wherein the remote computer is configured to:
receive, from
the at least one portable environmental sensing device, an alarm related to
the hazardous
condition or activation of panic button, and transmit to any of the portable
environmental
sensing devices an instruction to be propagated throughout the mesh network.
The instruction
is a request to check the safety of a user of the at least one portable
environmental sensing
device, an evacuation instruction, a risk mitigation instruction, or the like.
The remote
computer is further configured to display the location of the portable
environmental sensing
devices in a map of the work area, wherein the remote computer transmits the
map for
display on the any of the portable environmental sensing devices. The data is
sensed gas data,
wherein the hazardous condition is based on the sensed gas data exceeding a
threshold and
the remote computer is further configured to display the sensed gas data in a
map of the work
area. A size of the representation of the gas data is proportional to the gas
level. The remote
computer is further configured to request an emergency response at the
location of the at least
one portable environmental sensing device.
[0019] In an aspect, a system for providing an ad-hoc mesh network with
features as
described herein for an eyewash station includes a sensor disposed within the
eyewash station
to monitor a condition, the sensor adapted to communicate with nodes in a mesh
network;
and a digital sign, wherein the digital sign is adapted to receive data
related to the condition
from the sensor through the mesh network for presentation.
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[0020] In an aspect, a system for providing an ad-hoc mesh network with
features as
described herein for an eyewash station includes a sensor disposed within the
eyewash station
to monitor a condition, the sensor adapted to communicate with nodes in a mesh
network;
and a device in the mesh network configured to receive the communication from
the sensor
related to the condition and generate an alarm based on the condition meeting
a threshold or
criteria. The system further includes a digital sign in the mesh network,
wherein the digital
sign is adapted to receive the alarm from the device through the mesh network
for
presentation. The device in the mesh network is further configured to obtain
one or more of a
worker biometric datum and an area environmental datum. The device in the mesh
network
is further configured to transmit the alarm to a remote computer. The device
in the mesh
network is further configured to obtain an inventory of potential hazards from
an NFC tag in
the area near the eyewash station when an NFC radio of the device is brought
in proximity to
the NFC tag. A secondary alarm is generated based on at least one item in the
inventory.
[0021] In an aspect, a method of sensing a root cause or symptom of death or
injury of a
worker on a worksite includes obtaining sensor data from one or more body worn
sensors
attached to the body of the worker, wherein the sensor data relates to one or
more
physiological and behavioral effects of the root cause of worker death or
injury; analyzing the
sensor data to identify a safety issue; and modifying an authorization level
of the worker
when the analyzed sensor data identifies a presence of the safety issue,
wherein the
authorization level is stored on a device of the worker.
[0022] In an aspect, a method of sensing a root cause or symptom of death or
injury of a
worker on a worksite includes obtaining sensor data from one or more body worn
sensors
attached to the body of the worker, wherein the sensor data relates to one or
more
physiological and behavioral effects of the root cause of worker death or
injury; analyzing the
sensor data to identify a safety issue; and when the analyzed sensor data
identifies a presence
of the safety issue, communicating the safety issue to a safety device of the
worker for
presentation on the safety device. The method further includes communicating
the safety
issue to a second safety device of a second worker for presentation, wherein
the safety device
and the second safety device are peers in a mesh network.
[0023] In an aspect, a method of sensing a root cause or symptom of death or
injury of a
worker on a worksite includes obtaining sensor data from one or more body worn
sensors
attached to the body of the worker, wherein the sensor data relates to one or
more
physiological and behavioral effects of the root cause of worker death or
injury; analyzing the
sensor data to identify a safety issue; and when the analyzed sensor data
identifies a presence
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of the safety issue, communicating a request to check-in with the worker to a
safety device of
a second worker.
[0024] In an aspect, a system for providing a low-power ad-hoc mesh network
with
features as described herein for a remote jobsite includes a plurality of
network devices
comprising one or more worker monitoring devices and one or more area
monitoring devices,
wherein the network devices monitor at least one of a peer alarm, a worker
biometric datum
or an area environmental datum; and the network devices adapted to communicate
with one
another in a mesh network without a central network controller; wherein a
first network
device of the plurality of network devices transmits the peer alarm, the
worker biometric
datum or the area environmental datum to a second network device of the
plurality of
network devices for presentation on the second network device.
[0025] In an aspect, a system includes a plurality of network devices
comprising one or
more worker monitoring devices and one or more area monitoring devices,
wherein the
network devices monitor at least one of a peer alarm, a worker biometric datum
or an area
environmental datum, the network devices adapted to communicate with one
another in a
mesh network with features as described herein; and a network gateway, wherein
the plurality
of network devices transmits the peer alarm, the worker biometric datum or the
area
environmental datum to a remote computer through the gateway.
[0026] In an aspect, a system includes a plurality of network devices
comprising one or
more worker monitoring devices and one or more area monitoring devices,
wherein the
network devices monitor at least one of a peer alarm, a worker biometric datum
or an area
environmental datum, the network devices adapted to communicate with one
another in a
mesh network with features as described herein; and a device interface for a
remote-
networked device, wherein the plurality of network devices transmits the peer
alarm, the
worker biometric datum or the area environmental datum to the remote-networked
device,
wherein the remote-networked device is configured to further transmit the peer
alarm, the
worker biometric datum or the area environmental datum to a remote computer.
[0027] In an aspect, a method of sensing a root cause or symptom of death or
injury of a
worker on a worksite includes obtaining sensor data from one or more body worn
sensors
attached to the body of the worker, wherein the sensor data relates to one or
more
physiological and behavioral effects of the root cause of worker death or
injury; analyzing the
sensor data to identify a safety issue; and providing an alert to the worker
or a third party
when the analyzed sensor data identifies a presence of the safety issue. The
alert is
transmitted from the one or more body-worn sensors to a remote location via a
network
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connection. The alert is transmitted directly from the one or more body-worn
sensors to one
or more workers located on the worksite. The step of analyzing the sensor data
occurs within
the body worn sensor. The sensor data is transmitted via a wireless network
from the body-
worn sensor to a remote location for analysis of the sensor data. The remote
location
communicates with the body-worn sensor to alert the worker wearing the body-
worn sensor
when the analyzed sensor data identifies the presence of the safety issue. The
remote location
communicates with the third party on the worksite to alert the third party
that the analyzed
sensor data indicates the presence of the safety issue related to the worker
wearing the body-
worn sensor. The physiological effects include an effect on at least one of
ECG, heart rate,
blood pressure, breathing rate, skin temperature, posture, activity,
accelerometry, blood
pressure, pulse, body odors, blood alcohol level, glucose levels, and oxygen
saturation. The
behavioral effects include an effect on at least one of gait, walking
patterns, posture, eye
movements, pupil size, motion patterns, noises, and removal of the sensor from
the person
before a prescribed time. The body-worn sensors comprise one or more of a
heart rate
sensor, blood pressure sensor, gait detection sensor, olfactory sensor,
galvanic skin response
sensor, proximity sensor, accelerometer, eye tracking sensor, image sensor,
microphone,
infrared sensor, gas sensor, capacitive sensor, fingerprint sensor, networking
signal detector,
and location detector. The method further includes the step of storing the
sensor data and
comparing current sensor data to stored sensor data to determine a variance
indicating a
safety issue. The method further includes the step of storing typical sensor
data from a
plurality of workers and comparing current sensor data for the worker to
stored sensor data
for the plurality of workers to determine a variance indicating a safety
issue. The method
further includes the step of preventing the worker from accessing a system
after identifying a
safety issue. The method further includes the step of suggesting a behavior
change to the
worker to avoid a safety issue.
[0028] In an aspect, a system for providing a low-power ad-hoc mesh network
for a remote
jobsite includes a plurality of network devices comprising one or more sensing
devices and
one or more area monitoring devices, wherein the network devices monitor at
least one of a
peer alarm, a worker biometric datum or an area environmental datum; the
network devices
adapted to communicate with one another in a mesh network with features as
described
herein; wherein a first network device of the plurality of network devices
transmits the peer
alarm, the worker biometric datum or the area environmental datum to a second
network
device of the plurality of network devices for presentation on the second
network device.
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[0029] In an aspect, a network for connecting a plurality of network nodes
with features as
described herein includes a leader node; and a plurality of follower nodes,
wherein the leader
node transmits a sync message to the plurality of follower nodes indicating a
beginning of a
network interval, wherein the leader node and the plurality of follower nodes
transmit
information during a transmission period of the network interval and do not
transmit
information during a sleep period of the network interval, the leader node and
plurality of
follower nodes using less power in the sleep period than the transmission
period, the plurality
of follower nodes each comprising a timer, the timer adapted to time the
transmission period
and sleep period of a plurality of future network intervals in an absence of
continued receipt
of the sync message from the leader node during the plurality of future
network intervals.
When any of the plurality of follower nodes receive a sync message, the
follower node
transmits a message advertising one or more properties of the leader node
during a
predetermined period of the network interval. The one or more properties of
the leader node
includes at least one of a channel hopping sequence and a total number of the
network nodes
on the network. When any one of the plurality of follower nodes fails to
receive a receive a
sync message from the leader node, the follower node refrains from
transmitting a message
advertising a property of the leader node during the network interval.
Follower nodes each
comprise a counter for tracking the receipt of sync message from the leader.
The counter is
incremented when a sync message is received and decremented when a sync
message is not
received. When the counter of any one of the follower nodes reaches a
predetermined value,
the follower node initiates a procedure for finding a new leader node. When
the timer is
further adapted to time an expected receipt of future sync messages of future
network
intervals and when an actual receipt of the future sync message deviates from
an expected
receipt of the future sync message by a predetermined amount of time for a
predetermined
number of network intervals, the follower node adjusts the timer to more
closely correspond
with the actual receipt of the future sync message. The sync message includes
data indicating
the number of network nodes in the network. The length of the transmission
period is
determined by the number of network nodes in the network. The network nodes
are
environmental sensing devices. The information is assigned by reading an NFC
tag. The
information relates to a concentration of gas or an environmental attribute.
The network
nodes are environmental sensing devices, and the one or more properties is
assigned by
reading an NFC tag.
[0030] In an aspect, a network for connecting a plurality of network nodes
with features as
described herein includes a leader node; and a plurality of follower nodes,
wherein the leader
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node transmits a sync message to the plurality of follower nodes indicating a
beginning of a
network interval, wherein the leader node and the plurality of follower nodes
transmit
information during a transmission period and do not transmit information
during a sleep
period of the network interval, and wherein during a predetermined time of the
transmission
period of the network interval each of the follower nodes that received the
sync message
transmit a message advertising one or more properties of the leader node. The
one or more
properties of the leader node includes at least one of a channel hopping
sequence and a total
number of the network nodes on the network. When any of the plurality of
follower nodes
fails to receive a receive a sync message from the leader node, the follower
node refrains
from transmitting a message advertising a property of the leader node during
the network
interval. The message advertising a property of the leader node is broadcast
on a
predetermined subset of channels. A new follower node attempting to join the
network listens
on the predetermined subset of channels to receive the message advertising at
least one
property of the leader node to learn the at least one property of the leader
node to facilitate
the new follower node to join the network. At least one property comprises the
total number
of network nodes already on the network and the new follower node will refrain
from
attempting to join the network when the total number of network nodes exceeds
a
predetermined value. After a predetermined interval, the leader node refrains
from sending
the sync message and entering the sleep period for at least one network
interval and listens
for messages advertising at least one property of a different leader node. The
leader node is a
gas sensor. If the leader node receives a message advertising at least one
property of the
different leader node, the leader node starts a process to cease performing as
the leader node
and begin performing as a follower node of the different leader node. If the
leader node does
not receive a message advertising at least one property of another leader
node, the leader
node continues to perform as the leader node. The leader node and plurality of
follower
nodes use less power in the sleep period than the transmission period, the
plurality of
follower nodes each comprising a timer, the timer adapted to time the
transmission period
and sleep period of a plurality of future network intervals in an absence of
continued receipt
of the sync message from the leader node during the plurality of future
network intervals.
When the follower nodes transmit the message advertising the one or more
properties of the
leader node, the message is transmitted with a single hop such that a node
receiving the
message does not retransmit the message.
[0031] In an aspect, a method of operating a wireless mesh network with
features as
described herein includes the steps of: providing a plurality of nodes wherein
each node is
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operable to perform as a leader node or a follower node, wherein one node
performs to
identify itself as the leader node and one or more other nodes operate as
follower nodes;
wherein the leader node transmits a sync message to follower nodes indicating
a beginning of
a network interval, wherein the leader node and the follower nodes transmit
infolination
during a transmission period and do not transmit information during a sleep
period of the
network interval, and wherein during a predetermined time of the transmission
period of the
network interval follower nodes that received the sync message transmit a
message
advertising one or more properties of the leader node. The one or more
properties of the
leader node includes at least one of a channel hopping sequence and a total
number of the
network nodes on the network. When any of the plurality of follower nodes
fails to receive a
receive a sync message from the leader node, the follower node refrains from
transmitting a
message advertising a property of the leader node during the network interval.
The message
advertising a property of the leader node is broadcast on a predetermined
subset of channels.
A new follower node attempting to join the network listens on the
predetermined subset of
channels to receive the message advertising at least one property of the
leader node to learn
the at least one property of the leader node to facilitate the new follower
node to join the
network. The at least one property comprises the total number of network nodes
already on
the network and the new follower node will refrain from attempting to join the
network when
the total number of network nodes exceeds a predetermined value. After a
predetermined
interval, the leader node refrains from sending the sync message and entering
the sleep period
for at least one network interval and listens for messages advertising at
least one property of a
different leader node. The leader node is a gas sensor. if the leader node
receives a message
advertising at least one property of the different leader node, the leader
node starts a process
to cease performing as the leader node and begin performing as a follower node
of the
different leader node. If the leader node does not receive a message
advertising at least one
property of another leader node, the leader node continues to perform as the
leader node. The
leader node and plurality of follower nodes use less power in the sleep period
than the
transmission period, the plurality of follower nodes each comprising a timer,
the timer
adapted to time the transmission period and sleep period of a plurality of
future network
intervals in an absence of continued receipt of the sync message from the
leader node during
the plurality of future network intervals. When the follower nodes transmit
the message
advertising the one or more properties of the leader node, the message is
transmitted with a
single hop such that a node receiving the message does not retransmit the
message.
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[0032] In an aspect, a network with features as described herein for
connecting a plurality
of network nodes comprising: a first leader node; and a plurality of follower
nodes, wherein
the first leader node transmits a sync message to the plurality of follower
nodes indicating a
beginning of a network interval, wherein the plurality of follower nodes
transmit information
during a transmission period and do not transmit information during a sleep
period of the
network interval, and wherein during a predetermined time of the transmission
period of the
network interval each of the follower nodes that received the sync message
transmit a
message advertising one or more properties of the first leader node; and
wherein transmission
period, the first leader nodes listens for information advertising one or more
properties of a
second leader node. The message advertising a property of the second leader
node is
transmitted on a predetermined channel. The first leader node listens on the
predetermined
channel. The message advertising a property of the second leader node is also
transmitted on
a second predetermined channel. The first leader node also listens on the
second
predetermined channel. The first leader node listens for a period of time
greater than the
length of the network interval. When the first leader node receives for
information
advertising one or more properties of a second leader node, the first leader
node ceases
performing as a leader node and is adapted to begin a sequence to join the
second leader node
as a follower node. The plurality of follower nodes are adapted to detect an
absence of the
first leader node and begin a sequence to join a new leader node. The leader
node and
plurality of follower nodes use less power in the sleep period than the
transmission period,
the plurality of follower nodes each comprising a timer, the timer adapted to
time the
transmission period and sleep period of a plurality of future network
intervals in an absence
of continued receipt of the sync message from the leader node during the
plurality of future
network intervals. The network nodes are environmental sensing devices. The
information is
assigned by reading an NFC tag. The information relates to a concentration of
gas. The
information relates to an environmental attribute. The one or more properties
is assigned by
reading an NFC tag.
[0033] In an aspect, a network with features as described herein for
connecting a plurality
of network nodes comprising: a leader node; and a plurality of follower nodes,
wherein the
leader node transmits a sync message to the plurality of follower nodes
indicating a beginning
of a network interval, wherein the plurality follower nodes each comprise a
counter for
tracking the receipt of sync messages received from the leader node and the
counter is
incremented when a sync message is received and decremented when a sync
message is not
received, wherein any of the plurality of follower nodes will begin a process
of electing new
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leader node when the counter decreases to a predetermined value. The leader
node and the
plurality of follower nodes transmit information during a transmission period
and do not
transmit information during a sleep period of the network interval. The
follower node whose
counter has decremented to the predetermined value transmits a first nominate
message to
begin the process of electing a new leader node. The first nominate message is
transmitted
on a predetermined channel. The first nominate message is also transmitted on
a second
predetermined channel. The first nominate message includes data related to the
suitability of
the follower node sending the first nominate message to act as a leader node.
The data is
calculated from a strength and reliability of signals received from other
network nodes on the
network. The data is calculated by utili7ing at least one of an instrument
type of the follower
node, a battery state of charge, and past signal quality. The first nominate
message and data
are received by other network nodes and the data compared by the receiving
network nodes
to data related to a suitability of the receiving network nodes to act as a
leader node, wherein
the receiving network nodes reply with either a reply nominate message with
data indicating
a higher suitability to act as a leader node or a concede message if the
receiving network node
does not have a higher suitability to act as a leader node. When the follower
node sending
the first nominate message receives only concede messages, that follower node
assumes the
role of leader node and advertises at least one property of itself as a leader
node for other
network nodes to become follower nodes. When the follower node sending the
first nominate
message receives a nominate message with data indicating a higher suitability
to act as a
leader node, that follower node sends a concede message. The concede messages
are
transmitted on the predetemiined channel. The concede messages are also
transmitted on the
second predetermined channel.
[0034] In an aspect, a network with features as described herein for
connecting a plurality
of network nodes comprising: a leader node; and a plurality of follower nodes,
wherein the
leader node transmits sync message to the plurality of follower nodes
indicating a beginning
of successive network intervals, wherein upon nonreceipt of a predetermined
number of sync
messages by a follower node that follower node initiates a process of electing
a new leader
node by a sending a first nominate message that includes data related to the
suitability of the
follower node to act as a leader node. The plurality of follower nodes each
comprise a
counter for tracking the receipt of sync messages received from the leader
node and the
counter is incremented when a sync message is received and decremented when a
sync
message is not received, wherein any of the plurality of follower nodes will
begin a process
of electing new leader node when the counter decreases to the predetermined
value. The first
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nominate message is transmitted on a predetermined channel. The first nominate
message is
also transmitted on a second predetermined channel. The data is calculated
from a strength
and reliability of signals received from other network nodes on the network.
The data is
calculated by utilizing at least one of an instrument type of the follower
node, a battery state
of charge, and past signal quality. The first nominate message and data are
received by other
network nodes and the data compared by the receiving network nodes to data
related to a
suitability of the receiving network nodes to act as a leader node, wherein
the receiving
network nodes reply with either a reply nominate message with data indicating
a higher
suitability to act as a leader node or a concede message if the receiving
network node does
not have a higher suitability to act as a leader node. When the follower node
sending the first
nominate message receives only concede messages, that follower node assumes
the role of
leader node and advertises at least one property of itself as a leader node
for other network
nodes to become follower nodes. When the follower node sending the first
nominate
message receives a nominate message with data indicating a higher suitability
to act as a
leader node, that follower node sends a concede message. The concede messages
are
transmitted on the predetermined channel. The concede messages are also
transmitted on the
second predetermined channel. The network nodes are environmental sensing
devices. The
information is assigned to the node by reading an NFC tag. The information
relates to a
concentration of gas. The information relates to an environmental attribute.
The network
nodes are environmental sensing devices.
[0035] In an aspect, a method of providing information about a leader node to
a plurality of
follower nodes in a wireless mesh communication network with features as
described herein
comprising: designating the leader node; designating the plurality of follower
nodes;
designating one or more predetermined frequency ranges as a public channel;
from the leader
node and during a plurality of network intervals having a predetermined length
of time,
transmitting a sync message at a beginning of each network interval to the
plurality of
follower nodes; and during each network interval in which a sync message is
received by any
one of the follower nodes, transmitting from any of the plurality of follower
node receiving a
sync message, upon the least one public channel, a message advertising at
least one property
of the leader node after receipt of the sync message. The leader node also
sends a message
advertising at least one property of the leader node in any network interval
in which a sync
message is transmitted. The method may further include providing a new
follower node not
yet configured to receive the sync message; with the new follower node,
listening to the
public channel until the at least one property of the leader node is
broadcast; and from the at
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least one property, causing the new follower node to configure itself to
communicate with the
leader node on the next network cycle to join the network. The at least one
property of the
leader node comprises at least one of frequency hop parameters and the total
number of
leader and follower nodes on the network. The at least one property of the
leader node
comprises frequency hop parameters comprising a multiplier, an intercept and a
seed for
linear congruent generator. The frequency hop parameters further comprise
channel mask
parameters defining predetermined channels as either one of used and unused.
The frequency
hop parameters further comprise a length of time for the network interval. The
at least one
property of the leader node comprises the total number of leader and follower
nodes on the
network and wherein the new follower node will not attempt to join the network
if the total
exceeds a predetermined value. The leader node and follower nodes are
environmental
sensing devices.
[0036] In an aspect, a method of joining a new device to a mesh wireless
network with
features as described herein comprising: providing a mesh wireless network
comprising a
leader node and a plurality of follower nodes; designating at least one
predetermined
frequency range as a public channel; transmitting on the public channel
information
advertising at least one property of the leader node; with a new device to the
mesh wireless
network, listening on the public channel for the information transmitted
advertising at least
one property of the leader node; configuring the new device to follow the
leader device using
the at least one advertised property describing the leader node; with the new
device to the
mesh wireless network, receiving a sync message transmitted from the leader
node; and
requesting the leader node to join the mesh wireless network. The step of
transmitting on the
public channel information advertising at least one property of the leader
node is performed
by at least one of the follower nodes in response to receipt of a sync
message. The step of
transmitting on the public channel information advertising at least one
property of the leader
node is performed by the leader node after transmission of a sync message. The
at least one
property of the leader node comprises at least one of frequency hop parameters
and the total
number of leader and follower nodes on the network. The at least one property
of the leader
node comprises frequency hop parameters comprising a multiplier, an intercept
and a seed for
linear congruent generator. The frequency hop parameters further comprise
channel mask
parameters defining predetermined channels as either one of used and unused.
The frequency
hop parameters further comprise a length of time for the network interval. The
at least one
property of the leader node comprises the total number of leader and follower
nodes on the
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network and wherein the new follower node will not attempt to join the network
if the total
exceeds a predetermined value.
[0037] In an aspect, a method of joining a follower node to a leader node in a
wireless
mesh communication network with features as described herein comprising:
designating the
leader node; designating the plurality of follower nodes; designating one or
more
predetermined frequency ranges as a public channel; from the leader node and
during a
plurality of network intervals having a predetermined length of time,
transmitting a sync
message at a beginning of each network interval to the plurality of follower
nodes; during
each network interval in which a sync message is received by any one of the
follower nodes,
transmitting from any of the plurality of follower nodes receiving a sync
message, upon the
least one public channel, a message advertising at least one property of the
leader node after
receipt of the sync message; providing a new follower node not yet configured
to receive the
sync message; with the new follower node, listening to the public channel
until the at least
one property of the leader node is broadcast and received by the new follower
node; and from
the at least one property, causing the new follower node to configure itself
to communicate
with the leader node on the next network cycle to join the network. The method
further
includes providing a new follower node not yet configured to receive the sync
message; with
the new follower node, listening to the public channel until the at least one
property of the
leader node is broadcast; and from the at least one property, causing the new
follower node to
configure itself to communicate with the leader node on the next network cycle
to join the
network. The at least one property of the leader node comprises at least one
of frequency hop
parameters and the total number of leader and follower nodes on the network.
The at least
one property of the leader node comprises frequency hop parameters comprising
a multiplier,
an intercept and a seed for linear congruent generator. The frequency hop
parameters further
comprise channel mask parameters defining predetermined channels as either one
of used and
unused. The frequency hop parameters further include a length of time for the
network
interval. The at least one property of the leader node comprises the total
number of leader
and follower nodes on the network and wherein the new follower node will not
attempt to
join the network if the total exceeds a predetermined value. The leader node
is an
environmental sensing device. The devices are environmental sensing devices.
The leader
node and follower nodes are environmental sensing devices.
[0038] In an aspect, a network with features as described herein for
connecting a plurality
of network nodes comprising: a leader node; and a plurality of follower nodes,
wherein the
leader node transmits a sync message to the plurality of follower nodes
indicating a beginning
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of a network interval, wherein the sync message contains data indicating the
number of
network nodes in the network, wherein the leader node and the plurality of
follower nodes
transmit information during a transmission period of the network interval and
do not transmit
information during a sleep period of the network interval, wherein the network
interval is of a
fixed length of time, the transmission period is of a variable length of time
based upon the
number of network nodes in the network, and the sleep period comprises
remaining time of
the network interval after the transmission period. The transmit time is
divided between a
first transmit time for transmitting high priority data and a second transmit
time for lower
prior data. The first transmit time and the second transmit time are equal
length periods of
time. The leader node and plurality of follower nodes use less power in the
sleep period than
the transmission period, the plurality of follower nodes each comprising a
timer, the timer
adapted to time the transmission period and sleep period of a plurality of
future network
intervals in an absence of continued receipt of the sync message from the
leader node during
the plurality of future network intervals. When any of the plurality of
follower nodes receive
a sync message, the follower node transmits a message advertising one or more
properties of
the leader node during a predetermined period of the network interval. The one
or more
properties of the leader node includes at least one of a channel hopping
sequence and a total
number of the network nodes on the network. When the timer is further adapted
to time an
expected receipt of future sync messages of future network intervals and when
an actual
receipt of the future sync message deviates from an expected receipt of the
future sync
message by a predetermined amount of time for a predetermined number of
network
intervals, the follower node adjusts the timer to more closely correspond with
the actual
receipt of the future sync message. The network nodes are environmental
sensing devices.
The information is assigned to the node by reading an NFC tag. The information
relates to a
concentration of gas. The information relates to an environmental attribute.
[0039] In an aspect, a network with features as described herein for
connecting a plurality
of network nodes comprising: a leader node; and a plurality of follower nodes,
wherein the
leader node transmits a successive plurality of sync messages to the plurality
of follower
nodes indicating a beginning of successive network intervals, wherein the
leader node and the
plurality of follower nodes transmit information during a transmission period
of each network
interval and wherein the leader node changes a channel of the sync message in
subsequent
network intervals according to a channel change schedule and wherein the
plurality of
follower nodes change a channel to receive the sync messages of successive
network
intervals according to the same channel change schedule, and leader node does
not change a
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channel of transmission during the transmission period of the network
interval. The channel
change schedule changes the channel for each successive network interval. The
channel
change schedule changes the channel after a plurality of network intervals.
The channel
change schedule is changed according to a linear congruential generator. When
any of the
plurality of follower nodes receive a sync message, the follower node
transmits a message
advertising one or more properties of the channel change schedule. i.e channel
change
schedule is changed according to a linear congruential generator. The one or
more properties
of the channel change schedule comprises a seed, a multiplier and an intercept
for the linear
congruential generator. The channel change schedule further indicates channels
that are
unavailable to broadcast the sync message. The channel change schedule further
indicates
channels that are available to broadcast the sync message. The network nodes
are
environmental sensing devices. The information is assigned to the node by
reading an NFC
tag. The information relates to a concentration of gas. The information
relates to an
environmental attribute.
[0040] In an aspect, a static memory device comprising: an instrument
comprising at least
one of an environmental sensing device, a hazard detection device, and an
industrial safety
device, the instrument operating in a first sleep cycle in which the
instrument is generating
data related to the instrument type; a wireless radio for sending and
receiving information on
a wireless mesh network with features as described herein, the radio operating
a second sleep
cycle different from the first sleep cycle in at least one of period and
phase; and a shared
memory operatively connected to the instrument and the radio, the shared
memory
comprising static message memory comprising static messages related to the
instrument; an
outgoing memory portion that receives outgoing information from the instrument
and
transmits the outgoing information to the radio for transmission on the
wireless mesh
network, an incoming memory portion that receives incoming information from
the radio and
transmits the incoming information to instrument, the shared memory further
comprising
request and grant lines for the radio and for the instrument to allow the
radio and the
instrument to request and grant data to the incoming memory or the outgoing
memory,
wherein the shared memory is adapted to not allow the both the radio and the
instrument to
raise the grant lines and grant data to either the incoming or the outgoing
memory
simultaneously. The device further includes a radio internal buffer for
providing additional
memory space to the radio. The first and second sleep cycles differ in both
period and phase.
The shared memory further comprises an urgent line that provides an indicator
to the
instrument or the radio that the information in outgoing or incoming memory
portion should
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be accessed immediately. The information is assigned to the node by reading an
NFC tag.
The information relates to a concentration of gas. The information relates to
an
environmental attribute.
[0041] In an aspect, a network for connecting a plurality of network nodes
comprising: a
static memory device comprising: an instrument comprising at least one of an
environmental
sensing device, a hazard detection device, and an industrial safety device,
the instrument
operating in a first sleep cycle in which the instrument is generating data
related to the
instrument type; a wireless radio for sending and receiving information on a
wireless mesh
network with features as described herein, the radio operating a second sleep
cycle different
from the first sleep cycle in at least one of period and phase; and a shared
memory
operatively connected to the instrument and the radio, the shared memory
comprising static
message memory comprising static messages related to the instrument; an
outgoing memory
portion that receives outgoing information from the instrument and transmits
the outgoing
information to the radio for transmission on the wireless mesh network, an
incoming memory
portion that receives incoming information from the radio and transmits the
incoming
information to instrument, the shared memory further comprising request and
grant lines for
the radio and for the instrument to allow the radio and the instrument to
request and grant
data to the incoming memory or the outgoing memory, wherein the shared memory
is
adapted to not allow the both the radio and the instrument to raise the grant
lines and grant
data to either the incoming or the outgoing memory simultaneously; and a
wireless mesh
network communicating with the radio comprising: a leader node; and a
plurality of follower
nodes, wherein the leader node transmits a sync message to the plurality of
follower nodes
indicating a beginning of a network interval, wherein the leader node and the
plurality of
follower nodes transmit information during a transmission period of the
network interval and
do not transmit information during a sleep period of the network interval, the
leader node and
plurality of follower nodes using less power in the sleep period than the
transmission period,
the plurality of follower nodes each comprising a timer, the timer adapted to
time the
transmission period and sleep period of a plurality of future network
intervals in an absence
of continued receipt of the sync message from the leader node during the
plurality of future
network intervals. The network further includes a radio internal buffer for
providing
additional memory space to the radio. The first and second sleep cycles differ
in both period
and phase. The shared memory further comprises an urgent line that provides an
indicator to
the instrument or the radio that the information in outgoing or incoming
memory portion
should be accessed immediately. The information is assigned to the node by
reading an NFC
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tag. The information relates to a concentration of gas. The information
relates to an
environmental.
[0042] In an aspect, a mesh network device for connecting to, sending and
receiving
information on a mesh wireless network with features as described herein
comprising: an
instrument comprising at least one of an environmental sensing device, a
hazard detection
device, and an industrial safety device, a radio for transmitting and
receiving information on
the mesh wireless network; and a display for presenting a signal quality
indicator of a
connection of the radio to other nodes of the mesh wireless network, the
signal quality
indicator derived from a combination of the received signal strength (RSS) and
packet
receive ratio (PRR) of all the instruments in the mesh wireless network. The
instrument
multiplies an RSS of a most recent message received from each node in the mesh
network by
the PRR, which is the ratio of packets received from each device in the mesh
wireless
network to a number of expected packets from each respective device in the
mesh wireless
network. The RSS represents a most recent network hop taken by a packet. The
PRR is a
counter that begins at a predetermined number and is incremented and
decremented when
expected packets are received or not received, respectively. The increment and
decrement
values are 3 and 2, respectively. The signal quality indicator is based on the
product of RSS
* PRR for each node, summed and divided by a number of nodes in the network.
An alarm
sounds when the signal quality indicator drops below a predetermined level.
The infolination
is assigned to the node by reading an NFC tag. The information relates to a
concentration of
gas. The information relates to an environmental attribute.
[0043] In an aspect, a network with features as described herein for
connecting a plurality
of network nodes comprising: a leader node; and a plurality of follower nodes,
wherein the
leader node transmits a sync message to the plurality of follower nodes
indicating a beginning
of a network interval, wherein the sync message contains data indicating the
number of
network nodes in the network, wherein the leader node and the plurality of
follower nodes
transmit information during a transmission period of the network interval and
do not transmit
information during a sleep period of the network interval, wherein each of the
plurality of the
follower nodes randomly select an interval during the transmission period to
transmit data
and without respect to a time selected by any of the other follower nodes. The
time randomly
selected is with reference to beginning of the transmission period. The
network interval is of
a fixed length of time, the transmission period is of a variable length of
time based upon the
number of network nodes in the network, and the sleep period comprises
remaining time of
the network interval after the transmission period. The transmission period is
divided
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between a first transmit time for transmitting high priority data and a second
transmit time for
lower prior data and wherein the time randomly selected to transmit data is
with reference to
the beginning of the first transmit time and the second transmit time. The
first transmit time
and the second transmit time are equal length periods of time. The leader node
and plurality
of follower nodes use less power in the sleep period than the transmission
period, the
plurality of follower nodes each comprising a timer, the timer adapted to time
the
transmission period and sleep period of a plurality of future network
intervals in an absence
of continued receipt of the sync message from the leader node during the
plurality of future
network intervals. When any of the plurality of follower nodes receive a sync
message, the
follower node transmits a message advertising one or more properties of the
leader node
during a predetermined period of the network interval. The one or more
properties of the
leader node includes at least one of a channel hopping sequence and a total
number of the
network nodes on the network. When the timer is further adapted to time an
expected receipt
of future sync messages of future network intervals and when an actual receipt
of the future
sync message deviates from an expected receipt of the future sync message by a
predetermined amount of time for a predetermined number of network intervals,
the follower
node adjusts the timer to more closely correspond with the actual receipt of
the future sync
message. The network nodes are environmental sensing devices. The information
is assigned
to the node by reading an NFC tag. The infointation relates to a concentration
of gas. The
information relates to an environmental attribute.
[0044] In an aspect, a network with features as described herein for
connecting a plurality
of network nodes comprising: a leader node; and a plurality of follower nodes,
wherein the
leader node transmits a sync message to the plurality of follower nodes
indicating a beginning
of a network interval, wherein the sync message contains data indicating the
number of
network nodes in the network, wherein the leader node and the plurality of
follower nodes
transmit information during a transmission period of the network interval and
do not transmit
information during a sleep period of the network interval, wherein the
transmission period is
divided between a first transmit time for transmitting high priority data and
a second transmit
time for transmitting lower prior data. Each of the plurality of the follower
nodes randomly
select an interval during the transmission period to transmit data and without
respect to a time
selected by any of the other follower nodes and wherein the time randomly
selected to
transmit data is with reference to the beginning of the first transmit time
and the second
transmit time. The network interval is of a fixed length of time, the
transmission period is of
a variable length of time based upon the number of network nodes in the
network, and the
23
sleep period comprises remaining time of the network interval after the
transmission period.
The first transmit time and the second transmit time are equal length periods
of time. The
leader node and plurality of follower nodes use less power in the sleep period
than the
transmission period, the plurality of follower nodes each comprising a timer,
the timer
adapted to time the transmission period and sleep period of a plurality of
future network
intervals in an absence of continued receipt of the sync message from the
leader node during
the plurality of future network intervals. When any of the plurality of
follower nodes receive
a sync message, the follower node transmits a message advertising one or more
properties of
the leader node during a predetermined period of the network interval. The one
or more
properties of the leader node includes at least one of a channel hopping
sequence and a total
number of the network nodes on the network_ When the timer is further adapted
to time an
expected receipt of future sync messages of future network intervals and when
an actual
receipt of the future sync message deviates from an expected receipt of the
future sync
message by a predetermined amount of time for a predetermined number of
network
intervals, the follower node adjusts the timer to more closely correspond with
the actual
receipt of the future sync message. The network nodes are environmental
sensing devices.
The information is assigned to the node by reading an NFC tag. The information
relates to a
concentration of gas. The information relates to an environmental attribute.
[0045] These and other systems, methods, objects, features, and
advantages of the
present disclosure will be apparent to those skilled in the art from the
following detailed
description of the preferred embodiment and the drawings.
[0046] References to items in the singular should be understood to
include items in
the plural, and vice versa, unless explicitly stated otherwise or clear from
the text.
Grammatical conjunctions are intended to express any and all disjunctive and
conjunctive
combinations of conjoined clauses, sentences, words, and the like, unless
otherwise stated or
clear from the context.
BRIEF DESCRIPTION OF THE FIGURES
[0047] The disclosure and the following detailed description of certain
embodiments
thereof may be understood by reference to the following figures:
[0048] Fig. 1 depicts an overview of the worker safety system.
[0049] Fig. 2 depicts a challenging environment for networking.
[0050] Fig. 3 depicts a system for propagating an alarm in a mesh
network.
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[0051] Fig. 4 depicts frequency channel overlap.
[0052] Fig. 5 depicts a shared memory interface.
[0053] Fig. 6A depicts a list of instruments on a display.
[0054] Fig. 6B depicts a shadow gas display.
[0055] Fig. 7 depicts a script process for the wireless network.
[0056] Fig. 8 depicts a synchronization scheme and Fig. 8A depicts a method
for choosing
a leader from members of a network.
[0057] Fig. 9 depicts a leader election process.
[0058] Fig. 10 depicts a sleep cycle process.
[0059] Fig. 11 depicts the wireless network mesh architecture.
[0060] Fig. 12 depicts how the hardware enabling wireless network-
compatibility can be
extended to a platform using gateways to the Internet.
[0061] Fig. 13 depicts the wireless network fitting in a 7-layer OSI Model.
[0062] Fig. 14 depicts a method of the disclosure.
[0063] Fig. 15 depicts a block diagram of an embodiment of the disclosure.
[0064] Fig. 16 depicts a method of providing safety alerts.
[0065] Fig. 17 is an exploded view of various components of an exemplary gas
sensing
apparatus.
[0066] Fig. 18 is a cross-sectional view of an exemplary electrochemical gas
sensing
apparatus.
[0067] Fig. 19 depicts the electrochemical sensing apparatus of Fig. 18
without an
electrode stack.
[0068] Fig. 20 illustrates a cross-sectional view of an exemplary combustible
lower
explosive limit sensing apparatus.
[0069] Fig. 21 depicts a system for estimating heat index incorporated into
existing
detection equipment.
[0070] Figs. 22A-22C depict various configurations of a heat index estimation
system
connected to or incorporated into detection equipment.
[0071] Fig. 23 depicts a system for estimating heat index incorporating three
microphones.
[0072] Fig. 24 depicts a Wheatstone bridge circuit.
[0073] Fig. 25 depicts a gas sensor's span reserve and its baseline change
over time.
[0074] Figs. 26A-26C depict balanced bridge circuits.
[0075] Fig. 27A depicts a balanced bridge circuit.
[0076] Fig. 27B depicts the relationship between component value and baseline
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[0077] Fig. 28A depicts a balanced bridge circuit.
[0078] Fig. 28B depicts the relationship between component value and baseline.
[0079] Fig. 29A depicts a balanced bridge circuit.
[0080] Fig. 29B depicts the relationship between component values and
baseline.
[0081] Fig. 30A depicts a balanced bridge circuit.
[0082] Fig. 30B depicts the relationship between component value and baseline.
[0083] Fig. 31 depicts a balanced bridge circuit.
[0084] Fig. 32A depicts a balanced bridge circuit.
[0085] Fig. 32B depicts the relationship between component value and baseline.
[0086] Fig. 33 depicts a balanced bridge circuit.
[0087] Fig. 34 depicts a method for the production of a metallic copper filter
for hydrogen
sulfide.
[0088] Fig. 35 depicts a method for the production of a metallic copper filter
for hydrogen
sulfide.
[0089] Fig. 36 depicts a method for the production of a metallic copper filter
for hydrogen
sulfide.
[0090] Fig. 37 shows a graph of the relative capacity of different filters.
[0091] Fig. 38 shows a graph of sensor sensitivity over time in a hydrogen
sulfide
environment.
[0092] Fig. 39A depicts a three support post design of a gas sensing or
compensating element
of a gas sensor, before bead fabrication, with a cantilever placed through the
center of a
coated coil, and attached to the third support post.
[0093] Fig. 39B depicts the coil resting on the cantilever.
[0094] Fig. 39C depicts the cantilever touching an inside surface of the cod.
[0095] Fig. 40 depicts a three support post design of a gas sensing or
compensating element
of a gas sensor, after bead fabrication, the bead fabricated to coat both the
cantilever support
and the coil.
DETAILED DESCRIPTION
[0096] Referring to Fig. 1, in order to provide various services and
monitoring in a real-
time or near-real time fashion with respect to portable environmental sensing
devices, hazard
detection devices, and other safety instruments and devices, instruments and
devices is such a
system need reliable methods communicate with each other and/or with a remote
location, all
26
while in a challenging environment. This disclosure describes various aspects
of a worker
safety system, general components of which are shown in Fig. 1. The disclosure
describes
various communications strategies and technologies to enable various
applications and
services related to worker safety. In addition to showing the general
components of such a
system, Fig. 1 and the accompanying description provide an overview of the
communication
approaches and strategies, certain useful accessories, and various
applications enabled by the
worker safety system.
100971 Fig. 1
illustrates certain portable environmental sensing devices 108 and area
monitors 110, but it should be noted that other safety devices may be used
with the system
such as, multi-gas detection instruments, a gas detection instruments, a
portable
electrochemical gas sensing apparatuses, respirators, a harness, lighting
devices, fall arrest
devices, thermal detectors, flame detectors, or a chemical, biological,
radiological, nuclear,
and explosives (CBRNE) detector. In embodiments, environmental sensing device
may be as
described in "VENTIS PRO" U.S. Patent Nos. 9,000,910, 9,575,043, 6,338,266,
6,435,003,
6,888,467, and 6,742,382. In embodiments, area monitors such as described
herein as well as
in U.S. Patent Application Publication No. 2016/0209386, entitled MODULAR GAS
MONITORING SYSTEM and filed on January 15, 2016. Throughout this disclosure,
the
terms environmental sensing devices (or instruments) 108, area monitors 110,
and it should
be understood that any of methods, systems, applications, interfaces, and the
like described
herein may be used by any of the environmental sensing devices (or
instruments) 108, and
area monitors 110. In addition, the disclosure may refer to environmental
sensing devices
and area monitors collectively as "instruments". In embodiments, the
environmental sensing
devices 108 and area monitors 110 may communicate with one another using a
mobile ad hoc
wireless network (MANET) 104. As used herein, the term MANET is a continuously
self-
configuring, infrastructure-less network of mobile devices connected
wirelessly. One such
MANET that may be implemented is a mesh network. As used herein a mesh network
is a
network topology in which each node relays data for the network and all mesh
nodes
cooperate in the distribution of data in the network. Embodiments of the mesh
network
between environmental sensing devices 108 and area monitors 110 will be
described further
herein. In embodiments, the mesh network can enable communication between
components
of the system without the need of other conventional communications technology
for wireless
communication, such as WiFi, satellite, or cellular technologies. Because the
mesh wireless
network overcomes the
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challenge of operating a computer network where devices communication solely
with a
centralized device, such as a hub, switch or router, the network better
operates in challenging
environments where obstructions or distance prevent wireless communication
from a device
to a hub. By utilizing the mesh network, devices can communicate with one
another to
transmit messages from devices to other devices to communicate with one
another or to pass
information among devices or to eventually transmit the message to a device on
the perimeter
of the network for forwarding to another network, such as a device in the
cloud. Industrial
environments also typically represent challenging environments because sensors
may be
constantly moving or regularly changing location, the environment can be large
or remote
from public wireless infrastructure, large obstruction such as metal tanks may
block signals,
and the environment may be underground. This disclosure may also include
devices, nodes,
and the like communicating on a peer-to-peer network (P2P), which may be part
of a mesh
network. It should be understood that the embodiments described herein may
operate on a
mesh network, P2P network, or similar type of network. Fig. 1 also depicts
various
approaches to ultimately communicate data from the instruments to the cloud or
remote
server, such as via an API 114, smart device 118 or other mobile gateway 131,
a gateway
112, and a dock 122.
[0098] In embodiments, the mesh network 104 of this disclosure delivers "ready
to use"
wireless functionality to instrument platforms. When equipped with hardware to
be
compatible with the mesh network 104 and embedded firmware, instruments are
able to
communicate wirelessly with one another. Mesh wireless networking provides
instrument
features such as peer alarms, or "shadowing" readings from one instrument on
another
instrument's screen¨all within challenging environments typical to industrial
safety. The
mesh networking feature set is available for area monitors and portable
instruments and
enables interoperability, allowing a mixed network of portable and area
monitor instruments
to share readings and alarms.
[0099] Instruments 108 also communicate, via the mesh network with other mesh
network-
enabled infrastructure devices that further enable live monitoring, automated
messaging, and
location awareness, such other mesh network-enabled infrastructure devices
including
network gateway device (also referred to herein as "gateway") 112 and docks
122. For
example, a network gateway device 112 may be placed in location in proximity
to
instruments, devices, computers, vehicles, equipment, and the like to enable
communication
with a network infrastructure. The instruments may communicate with the
network gateway
device 112 through the mesh network 104, and in embodiments, the data may be
ultimately
28
communicated, to a cloud server, via networking technology, such as WiFi,
cellular, satellite,
and the like, for downstream uses, for example by a remote server as described
herein. There
may be two-way communication through the gateway 112 such that remote servers
or
applications running in the cloud may be used to control, configure or
otherwise
communicate with the instruments 108, 110 through the gateway 112.
1001001 In embodiments, the dock 122, or docking station, may be used
with the
instrument to provide predictive diagnostic information, as described in U.S.
Patent No.
6,442,639, entitled Docking Station for Environmental Monitoring Instruments.
The docking
station or gateway 112 (or API 114/Smart Device 118 / mobile gateway 131 as
described
herein) may be connected, typically via the Internet, to a remote server 130,
and exposure
data, calibration data and diagnostic data are communicated from the
instrument to the
docking station and from the docking station to the remote server 130.
Mathematical analysis
of the collected data from all available sources is performed by the remote
server 130 to,
among other things, generate predictive warnings to alert the users of
potential instrument
faults, thus allowing preemptive maintenance, incident management, and the
like. The
analysis methods include principle component analysis and other statistical
methods, fuzzy
logic and neural networks. In embodiments, the worker safety system can take
data from
components of the system, store such data, generate reports to be sorted based
on the data and
communicate the data to a user. Such data communicated to a user can include,
for example,
events, need for calibration/bump testing, maintenance record, alert that
settings are incorrect
or sub-optimal, and error codes. The remote server 130 may also generate
alerts to send to
users, can change settings remotely, can alert a user if another user has an
alarm and provide
information on where to respond, and other end use applications as described
herein.
[001011 The mesh network may be tailored to the unique needs of worker-
to-worker
communication. In an embodiment, the wireless network may be applied to the
challenge of
hazardous gas detection ¨ relaying alarms and readings among a group of gas
detection
instruments in the challenging environments described herein. Referring to
Fig. 2, a particular
challenging environment is shown. Instruments 108 and 110 communicate with a
beacon
102, a tag 132, a wearable 134 and to a gateway 112 through an external
cellular, satellite, or
WiFi network 136 to the cloud 138. A large metal tank 140 is present in the
environment
though which signals will not pass. Fig. 2 illustrates that instruments 108
and 110 either
communicate with nearby instruments 108 and/or 110 and not with remote
instruments or
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instruments blocked by obstructions, such as tank 200. Instruments 108 and 110
interoperate
to create paths for data between instruments 108 and 110 which are not
directly connected.
[00102] True mesh communications allowing sensors to communicate directly with
one
another is novel in portable gas detection. Daisy-chain alarms, such as
perimeter or fence
line, for area monitoring exist, but current wireless implementations for
portable devices 108
only relay information to a central display or "controller", such as a laptop
computer or a
dedicated display device.
[00103] This disclosure describes the features of the wireless network, and
how these
features work in concert to address the challenges of worker-to-worker
communications.
These challenges include ease of use, difficult environment, dynamic network
topologies, and
power consumption.
[00104] The mesh wireless network 104 may relay an alarm notification from one
instrument to another instrument. "Peers" could be, for example, two portable
instruments
worn by two members of a crew, three area monitors surrounding a work zone, or
some
combination thereof. Peers are equals in the network and information may be
exchanged in
both directions.
[00105] Points in a network are called nodes. Nodes in the mesh wireless
network 104 may
include instruments 108, 110, devices 118, beacons 102 (which are described
further herein),
gateways 131, 112, docks 122, and the like. Most wireless networks have a
coordinator node,
a single entity in the network to coordinate the activities of others. In star
network topologies
such as WiFi, the coordinator node is the access point. In Bluetooth, the
coordinator node is
the master (smartphone or PC). In other mesh protocols like Zigbee and
WirelessHART, a
dedicated coordinator node is used. ZigBee is a registered trademark of
Philips Electronics
North American Corporation. WirelessHART is a registered trademark of Hart
Communication Foundation. In all of these cases, the coordinator role is
necessary for the
network to operate and is a dedicated device for performing the coordinator
function. The
coordinator manages routing tables, sets Time Division Multiple Access (TDMA)
slots,
coordinates frequency hopping, etc. The coordinator may be line-powered for
reliability and
availability for communication. For example, in WirelessHART, the role of the
coordinator
is vital, a backup coordinator is held in reserve, just in case the primary
coordinator fails.
[00106] A coordinator node is not required with the mesh wireless network 104
of the
present invention, as it is a truly ad-hoc network. Any collection of two or
more instruments
may form a network, without the need for any infrastructure. The mesh network
104 can
tolerate the loss of any member, at any time, without warning because each
device
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communicates with all other devices within range and maintains a database of
devices from
whom communications have been received. When messages from a device have not
been
received within a predetermined period of time, the device is removed from the
database.
[00107] For security, every node has a default private encryption key which
may be
changed. By changing the encryption key, a network can be kept secure but also
can be
altered to keep mesh networks intended to operate separately in the same space
from
communicating with one another, such as keeping the network of different
contractors in an
industrial environment from contacting one another. The network is blind to
nodes operating
on a different encryption key. Also for security, dynamic frequency hopping,
as described
below, is implemented so that the channel on which the network will be
communicating is
pseudo-random and constantly changes. Finally, security may be implemented by
bringing a
node into contact or near-contact with a near field communication device
("NFC") to identify
and authorize that node on the network, as described below.
[00108] High bandwidth, low latency MANETs, like those used on the
battlefield, are
extremely sophisticated. They involve multi-radio units and significant
communications
processing hardware, but wireless environmental sensing such as gas detection
may not
require this level of performance. The mesh network 104 excels at sharing a
small amount of
information, with a plurality of other instruments, with relatively low (such
as a few seconds)
delay without the complexity of existing high-bandwidth, low latency MANETs.
One feature
eliminating the complexity of other MANETs is that the mesh network 104
assumes
messages reach their destination
[00109] In embodiments, the mesh network 104 emphasizes energy efficiency
using power-
efficient broadcasts of information. The network 104 operates on a constant
network
interval, for example 1 second. Within the network interval is a period of
broadcasting and a
period of sleep cycling. Moreover, the length of the period of broadcasting is
altered in the
mesh network 104 based upon the number of devices currently joined to the
network, such
that a network with few devices can be even more power efficient by increasing
the period of
sleep cycling within each network interval, as further described below.
[00110] In embodiments, the mesh network 104 may not be a long-range link. The
mesh
network 104 may typically operate at distances of 100-200m between individual
nodes, and is
not intended for remote monitoring of a distant site. The mesh network 104
feature set is
meant to communicate between, and alert workers within, the same group and
working in the
same vicinity. It provides acceptable range and coverage by leveraging the
mesh topology.
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[00111] The mesh network 104 shares information and alarms with other
instruments
without a dedicated coordinator node, or any fixed nodes for that matter.
[00112] In embodiments, the mesh network 104 provides a setting-free, self-
forming, self-
healing, resilient wireless network without a dedicated coordinator node. As
described below,
there are no user settings required, no channel selection, and no PAN id to
enter. In one
embodiment, with the intuitive action of touching two instruments together, a
network may
be formed. Touching another instrument to an existing member of a network
joins the new
instrument into the network if the instrument is not already in a network
itself. Touching the
instruments may be a tap, double tap, bump, both being shaken together, a
touch of the tops
of the instruments, a touch of the bottoms of the instruments, and the like.
In embodiments,
if when the instruments are tapped it is determined that they are each already
members of a
different network, each instrument may be prompted to leave their network, and
if one leaves,
upon re-tapping, the network joining may be successful. In a distributed
fashion, the network
is maintained and adapts as member instruments come and go and move about the
challenging RF environment typical of industrial settings.
[00113] The wireless network's adaptability and resilience is a result of an
emphasis on
wireless diversity. This diversity takes three forms: space diversity,
frequency diversity, and
time diversity. Space diversity involves transmitting a wireless signal over
several different
propagation paths, with the understanding that different paths experience
radically different
RF impediments. Space diversity is the reason most WiFi access points have
more than one
antenna ¨ even separating two antennas by a few inches significantly reduces
"dead spots" in
coverage caused by reflections off walls and other objects. Instruments
operating on the mesh
network 104 are too small to benefit from multiple antennas; however a mesh
network such
as 104, where messages can take alternate paths through a network provides the
same effect,
even with as few as three nodes- as illustrated by the example above.
[00114] Frequency diversity, also known as frequency hopping, is a scheme
where a
communication system regularly changes the frequency (channel) used for
communications.
Frequency diversity helps overcome some sources of dead zones because areas of
destructive
interference due to RF reflections (called multi-path fading or multi-path
interference) occur
at different locations at different frequencies. Frequency diversity also
helps avoid
interference with other users of the wireless spectrum. If a nearby device is
using only a
portion of the spectrum, only some transmissions are impacted. In embodiments,
the mesh
network 104 may implement a slow-hopping scheme. Each network interval (for
example,
about once per second), the network may switch frequencies, preferably using a
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pseudorandom sequence. This is in comparison to a "fast-hopping" system like
Bluetooth,
which changes frequencies 1,600 times per second. Fast-hopping is appropriate
when an
interruption of just milliseconds would matter ¨ like streaming audio from a
phone to a
stereo. Slow hopping requires less computational horsepower (saving power) and
simplifies
the process of locating and joining networks.
[00115] Time diversity involves transmitting the same information at different
instances of
time. The chances of a message getting blocked multiple times is far lower
than if the
message is sent just once. In the mesh network 104, time diversity may be
achieved by at
least two means. First, instruments on the mesh network 104 may transmit their
information
quite often ¨ at least once every few seconds. Second, each regular
transmission from an
instrument on the mesh network 104 may be a complete (yet compact) snapshot of
the
instrument's current condition (called state-based communications). For
example, an
instrument on the network 104 may be a gas sensor which transmits its current
state to the
network, including information identifying it as a gas sensor, a gas reading,
an alarm status,
whether a panic between has been pressed, instrument status, etc. In
embodiments, nothing
important is sent just once (event-based communication), for example in a gas
sensor the
snapshot of the devices current condition may be sent every network cycle, for
example. If
one transmission is lost, for example due to a collision with another
instrument's
transmission, the next message is likely to make it through. Time diversity is
particularly
effective when combined with frequency diversity, as the next transmission
will use a
different part of the RF spectrum that has different RF impediments.
[00116] In embodiments utilizing mesh networking, which is a collection of
wireless nodes
that communicate with each other either directly or through one or more
intermediate nodes,
the nodes may operate in harmony, cooperatively passing information from point
A to point
B by making forwarding (routing) decisions based on their knowledge of the
network.
Through this collaboration, a mesh network can extend over long distances and
operate in
spite of very poor RF "line of sight" conditions between some of the nodes of
the network.
[00117] Through the process called binding, which relates to the process of
placing two or
more nodes into the same network, the wireless network 104 may automatically
correct
settings mismatches between instruments, such as the timing of the network
interval and the
frequency hopping sequence. In this way, any errors made in network setting
that a user, for
example entered by an industrial hygienist, or administrator can be corrected
automatically
when two instruments bind.
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[00118] The wireless network may implement a radio incorporating mesh
networking
technology. The radio uses relatively common IEEE 802.15.4 radios similar to
those used in
ZigBee. The radio adds a network operating system layer that implements a self-
forming
mesh routing layer. Networking functions are distributed with the network, it
requires no
central coordinator node for operation. All nodes can forward packets,
creating and updating
their own routing tables.
[00119] In embodiments, the end application, such as a gas detection
instrument 110 or 108,
interacts with the networking layer using a novel approach. The radio module
implements a
virtual machine, with access to nearly all radio module and networking
functions. The
behavior of the radio and network can be tailored and highly optimized by the
application
layer to operate the mesh network 104 of the present invention to the specific
needs of the
application using custom scripts. The wireless network behaviors can be highly
tailored to the
unique needs of gas detection.
[00120] In embodiments, the wireless network may be implemented in scripting
("radio
scripts", or "script" herein). Wireless network scripts run within the network
operating
system (also referred to as "radio firmware" or "firmware").
[00121] The network operating system platform also includes a hardware
abstraction layer
(HAL) that insulates the application from radio hardware specifics. This
allows the same
script to run on different supported radio hardware without modification.
[00122] The radio modules use radios compliant with IEEE 802.15.4. These
radios can be
operated at different frequencies. The wireless network uses the 2.4GHz band
due to its
nearly universal world-wide acceptance (without the need for end-user
licenses) and
improved performance in industrial environments with lots of metal
obstructions. In
embodiments, there may be 16 available channels, each 2 MHz wide, in a 2.4GHz
802.15.4
system.
[00123] Referring to Fig. 4, the channels may overlap with the same spectrum
used by Wi-
Fi, Bluetooth, and other consumer and industrial systems, so the wireless
network may be
designed to coexist with other wireless systems through the diversity schemes
introduced
herein, particularly frequency diversity.
[00124] With respect to power conservation, sleep cycling is a process where
the entire
mesh network communicates with one another during a regular, but small window
of time. It
is important to understand that the entire network wakes and sleeps at the
same time. The
advantage of sleep cycling is reduced power consumption. By allowing nodes to
sleep while
they are off the air, the average current consumption is reduced. The ratio of
communication
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time to sleep time may be directly proportional to average current
consumption. If radios only
spend 10% of their time in the communication period, their average current
consumption will
be roughly 10% of their on-state current (sleep current is negligible). The
advantage of sleep
cycling in a mesh network is its simplicity ¨ when it is time to talk, the
mesh network
behaves as if it were always on. There is no need to plan time slots for each
pair of nodes or
understand the physical topology of the network, which would be easier to do
with a
dedicated coordinator. The challenge in sleep cycled networks is keeping
everyone on the
same schedule, but can be overcome with synchronization techniques as
described herein.
[00125] Both the instrument itself (for example, a gas detector) and the
wireless network
radio may employ sleep cycling. Most instruments wake once a second (or two
seconds in
some cases) to measure an environmental parameter, such as gas, and perform
housekeeping
functions before going back to sleep to reduce average power consumption. As
discussed
herein, the wireless network sleeps too, under the direction of the network
leader. In
embodiments, these two sleep cycles cannot be synchronized. Different
instruments have
different wake/sleep schedules, and the rates at which gas concentrations are
measured are
subject to considerable regulation. A system where gas measurement rates are
not
deterministic would be difficult to certify. Communicating between these two
sleeping
systems is difficult.
[00126] To address the challenge of the radio and the instrument operating on
different wake
and sleep cycles, nodes of the mesh network 104 may employ a shared memory
interface
between the radio and instrument. Described functionally, the shared memory
interface may
be analogous to a mailbox. Anyone can stop at the mailbox and insert items for
someone
else, while at the same time checking to see if any in-bound mail has arrived.
A second
person can do the same. The two people don't need to be at the mailbox at the
same time to
exchange information. If there is something urgent in the mailbox for the
other person, the
indicator flag may be raised to ensure they pick it up at the next
opportunity. If two people
arrive at the same time and try to check/deliver mail simultaneously, they
could end up
dropping some mail on the ground in the confusion. The shared memory interface
uses
"Request" and "Grant" lines, one each for the radio and instrument to ensure
two people
don't reach into "the mailbox" at the same time. The arbiter is a special
circuit that prevents
two "Grants" from being active at any moment in time. The shared memory also
implements
an "Urgent" line that is the equivalent of the indicator flag on the mailbox.
[00127] Referring to Fig. 5, the shared memory is described structurally. The
shared
memory is a simple 32kB static RAM chip 502. Within this memory space, the
wireless
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network implements different storage locations for different types of
information. Commonly
sent messages have dedicated memory locations (Static Messages 504). An
example of a
static message would be a message indicating the type of instrument attached
to the node.
The radio's 520 configuration and status may be communicated using a bank of
registers 508.
Incoming 510 and outgoing 512 mailboxes handle all messaging not covered by a
Static
Message type. Finally, some memory is allocated to the radio module, a radio
internal buffer
514, for its internal use, because the memory structure available within the
network OS may
be limited.
[00128] Furthermore, every node (for example, portable environmental sensing
devices 108
and area monitors 110 in the mesh network 104) include a precision timer
integrated circuit
522, as described below.
[00129] In embodiments, the host instrument 518 may control nearly everything
about the
wireless network radio. Configuration messages may be provided to modify the
vast majority
of the radio settings. In a couple of cases, the instrument 518 may modify
settings through
registers as well. The instrument 518 may also control the state of the
wireless network radio
520 and can place the radio 520 into Sleep or Off Air modes at will.
[00130] In embodiments, instruments compatible with the mesh network 104 may
send a
surprisingly small variety of messages. The most common message is instUpdt().
The
payload of this message is a snapshot of the instrument status.
[00131] In order to minimize network traffic, the wireless network may
implement two
different flavors of instUpdt() message. If all is normal with the instrument,
and all sensor
readings are near "zero", a short ("terse") version of the instUpdt() message
is sent. The terse
version essentially says "I'm Ok". If the instrument is detecting gas or
experiencing any
alarm, the more detailed "verbose" format is sent, which includes all sensor
readings and
alarm details.
[00132] In embodiments, a verbose message with 6 sensors may be around 40
bytes. The
terse form of the message may only be 10 bytes long. An instrument may send
status
messages in the terse format unless: another instrument requests it to go
verbose (for example
if it wants to display real-time gas readings for a confined space entry), a
gas reading is above
the wireless deadband (currently set at 25% of the low alarm level), or the
instrument is in
alarm for any reason (including panic and man-down).
[00133] When one instrument wants to see all information from another
instrument (for
example, when an attendant wants to display real time readings from a confined
space
entrant), even near-zero readings, it can request the instrument send the
verbose format by
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issuing the setVerbose() message. For example, an instrument may be requested
to go into a
verbose mode when the instrument is being shadowed, such as when the
instrument wearer
enters a confined space. The payload of this message may include the number of
seconds for
which the sender is requesting verbose messages be sent.
[00134] A set of messages termed "identify" may provide the relatively static
information
needed to correctly interpret the payload of the instUpdt() message. These
messages may
contain configuration details about the instrument, including numbers and
types of sensors,
instrument type, serial number, current user and current site. When an
instrument first joins a
network, it may broadcast this information for other instruments already in
the network to
save. Instruments that join later, or for any reason need to fill in their
details about another
instrument can request an instrument resend this data (broadcast or unicast)
using the idReq()
message.
[00135] Using the information found in instUpdt() and the identify messages, a
relatively
complete picture may be generated to reflect the current status of any
instrument in the
network.
[00136] Referring to Fig. 6A, as instUpdt() messages arrive, receiving
instruments are
expected to extract the relevant information, correlate it to the correct
instrument, and update
their internal peer status list accordingly. When a message arrives from a new
instrument, as
indicated by a new media access control ("MAC") address, the instrument is
added to the
peer list and missing information is filled in from the identify messages. A
MAC address is a
unique identifier assigned to network interfaces for communications at the
data link layer of a
network segment that uniquely identifies the device on the network. When an
instrument
leaves the network (e.g., user selects "disconnect", or powers down the
instrument), it sends a
special "disconnecting" message, which may be send repeatedly, and should be
removed
from the peer list of other nodes on the network. Instruments expect to hear
an instUpdt()
message from each peer in each network cycle. If these messages stop after the
expiration of
a predetermined number of network cycles, the peer instrument may be marked
"lost" and a
warning may be sounded (if enabled).
[00137] Referring to Fig. 6B, shadow gas is a term used to describe the
instrument feature
where one instrument can display the real-time readings of another instrument
remotely,
which may be particularly helpful for confined space use cases. Shadow gas
feature is
activated by selecting a peer instrument from the List of Instruments, as
shown in Fig. 6A. A
screen representing the remote instrument may be displayed and update in near
real-time. In
this case, even near zero gas readings may need to be displayed, to provide
confidence to the
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user that the readings are indeed being relayed to the observer. In addition
to the shadow gas
readings, the other instrument's location may be displayed, such as on a map.
[00138] To enable this functionality, some combination of the identify
messages and
setVerbose() are used. When a remote instrument is selected, the instrument
will gather
information such as the username, sensor details, and the like to populate the
Shadow Gas
display. The remote instrument will be set to transmit verbose readings.
[00139] One of the ways to improve robustness of a wireless network is to
enlist the help of
the end user such as by displaying a relevant signal quality indicator on the
user's screen,
analogous to the "4 bars" displayed on most cellular phones. The signal
quality indicator
helps users diagnose connection issues themselves, reducing support calls. It
also warns users
of an impending loss of communication, so they can address it. Preferably, the
signal quality
indicator displays an indicator of the quality of connections of all of the
nodes on the
network. Alternatively, the signal quality indicator displays the quality of
the connection
between the instrument and a predefined node on the network. Alternatively,
the signal
quality indicator displays the quality of a connection between the instrument
and the
strongest direct connection with another node.
[00140] For the mesh network 104, the signal quality indicator may be derived
from a
combination of the received signal strength (RSS) and packet receive ratio
(PRR, or "Health
Counter") of all the instruments in a given network. This is unlike a cellular
phone, which
displays only the signal quality between a phone and the nearest tower.
[00141] The RSS is available from the MAC layer of the radio for each received
packet. The
instrument records the RSS from the last message received from each peer
instrument. The
signal strengths represent the last network hop taken by the message and do
not necessarily
reflect the weakest link in the path taken. The PRR or health counter is a
measure of the
recent number of received messages versus the number of expected messages
(based on the
network interval). The PRR or health counter is tracked for each peer. The PRR
or health
counter is a counter that begins at a predetermined number, such as 10, and is
incremented
and decremented when expected packets are received or not received,
respectively. The
increment and decrement values may not be the same, such as incrementing by 3
and
decrementing by 2. When the health counter reaches zero, the node presumes
that it is lost
from the network.
[00142] The signal quality indicator is based on the product of RSS * PRR for
each node,
summed and divided by the number of instruments in the network. Alerts may be
set for one
or more remote nodes to monitor signal strength, and a warning may occur when
the strength
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drops below a threshold and an alarm may issue when signal drops out. A
critical alert may
be set when the signal being monitored is a safety monitoring point.
[00143] The wireless network feature set may be implemented in several parts
and layers of
an instrument, including the instrument firmware, radio scripts, and radio
firmware. As
features evolve, each part of the system may need to be updated. A robust
system may be
needed to allow for field updates while ensuring all the pieces remain
compatible.
[00144] Referring to Fig. 7, wireless network scripts may be written in a
scripting language
developed using the portal IDE 703. The script 702 (Script.py) can then be
"compiled" to
bytecode for a specific radio module (or "platform") into a .spy file 704
(e.g., SM200 radio
module and an SM220 radio module have different .spy files). The Portal IDE
also provides a
checksum for the compiled script (used later). A converter application 708,
such as the
Windows-based PC application SpyConverter may be used to convert the .spy file
type 704
into a .bin file 710. The .bin file 710 is converted to a .hex file using the
programming utility
(e.g., JFLASH) and merged with other parts of the instrument firmware. The
script's
checksum (from the Portal IDE), Radio Hardware Version (e.g., SM200=0x01 ...),
and the
script version (3 bytes - Major.Minor.Build) may be appended to the script
file, again using
the programming utility, for use by the instrument in checking the radio's
programming. The
checksum and version (including hardware and script) should match what is
reported by the
radio module, or an error may be generated. The complete .hex file may be
loaded into
instrument memory by the instrument bootloader, like any other part of
instrument firmware.
Accessory Software, iNet, servers, worker safety system, and the docking
stations have no
knowledge that the instrument firmware image actually also contains firmware
for the radio.
[00145] At power up, the instrument may check the radio module's script
version, which
may be displayed on the startup screen and available through Modbus. When the
instrument
detects an out of date script, it may begin the script update process. This
process uses a
special communications port between the radio and instrument. The instrument
uses an
embedded Script Uploader utility (similar to a bootloader) to transfer the
file (in blocks) from
instrument memory to radio memory. When complete, the new script is checked
for validity
before the radio module is rebooted and normal operation commences.
[00146] Once the wireless network script is running, the instrument may also
check the radio
module's firmware version that comes preloaded on the radio module. It is
displayed on the
startup screen, and available through Modbus. The instrument checks to see
that the radio
module firmware version is same or newer than the revision the instrument
firmware and
script are expecting (this value is hard coded in instrument firmware). This
approach is based
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on the understanding that, in embodiments, features may be added, but not
removed, from the
radio network operating system. If the radio module version is out of date
(not supported), the
instrument may disable wireless network functionality (instrument continues to
operate) and
instruct the user to get the radio module firmware updated.
[00147] Once the wireless network script is running, the Radio module type (or
Platform,
e.g., SM200, etc.) may be read by the Radio module, translated into a single-
byte value (e.g.,
SM200=0x01 ...) and posted to the host interface as the Radio Hardware
Version. The
instrument may post this value to modbus. At power up, the instrument may
compare the
Radio Hardware Version to the value appended to the programmer hex file. This
may allow
the instrument to confirm any future instrument firmware or radio script
updates are
compatible with the radio hardware installed.
[00148] Instruments compatible with the mesh network include any described
herein as well
as a barometer, which may be operable in an indoor location. The readings may
be available
using the host interface. The barometer reading may be saved to a Modbus
register to enable
factory testing. Using the barometer the altitude of the instrument can be
detected. This
feature can be used, for example, to determine the floor level of the
instrument, such as in an
underground facility. A compensation barometer, implemented as an instrument
on the
network located at, for example, ground level can be used to determine
atmospheric pressure
at the reference level. Using the detected atmospheric pressure and the
reference atmospheric
pressure, the floor level of the instrument can be determined. This
information may be
relayed through the network, and possibly through a gateway and to an external
network,
where the location of instruments can be displayed on a computer to show the
location of
instruments in latitude, longitude and elevation.
[00149] While the wireless network is operating normally, it is sleep-cycling,
frequency-
hopping, and encrypted. In this mode, it may be difficult to perform certain
activities like
testing the radio in manufacturing or performing an over the air update of
radio module
firmware. For this reason, a Test Mode may be implemented. In test mode, the
radio stops
sleeping and frequency hopping, and switches the encryption key to one that
can be shared
with service centers, manufacturing applications, etc. In test mode, the radio
may respond to
several external wireless commands that allow factory testing of the radio and
over-the-air
updates to radio firmware. Test mode may be accessible, in embodiments, by
writing a
special password to the test mode Modbus register (using software like DUSS,
or a
manufacturing application).
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[00150] In embodiments, every node (for example, portable environmental
sensing devices
108 and area monitors 110) in the mesh network 104 may include a precision
timer integrated
circuit 522. This timer 522 should be a stable timer, for example, stable to
within a few
milliseconds over an hour or more.
[00151] In most networks, synchronization is handled by a dedicated
coordinator node. In
the mesh network 104, this job is performed by one of the members of the
network, called the
leader. The most important job of the leader is to synchronize the mesh. The
leader regularly
broadcasts a wireless synchronization message to members of the network that
marks the
beginning of the period that the network is able to actively communicate,
otherwise known as
a "sync message" or sync() message. Follower nodes maintain synchronization
with the
leader's instructions. The leader node becomes the "master timekeeper" and all
other nodes
adjust their internal timers' interval and phase to match the leader's timer.
[00152] These synchronization messages issued by the leader may also contain a
value that
represents the number of nodes the leader believes are currently in the
network. The leader
bases this value on the number of instruments that are reporting messages,
such as status
messages or readings messages, such as gas status readings. The amount of time
the network
remains awake is preferably dependent on the size of the network to save
power. Each node
calculates its awake time, based on the value in the last synchronization
message it received.
For example, a network with only 3 instruments will spend much less time awake
than a
network with 20 instruments, saving power.
[00153] In embodiments, if a follower node doesn't receive a sync() message,
it may still
wake up at the prescribed time and exchange messages with other nodes. Because
the
hardware timers are so stable, even if several synchronization messages are
missed or
corrupt, the nodes continue to wake at the right time. Followers are not
dependent on the
leader for second-to-second transmissions, however, if synchronization
messages stop
altogether, a follower may eventually decide that it has lost the leader and
will begin the
process of rejoining the network, as described herein. Each time the network
wakes, it uses
the next channel in the frequency hopping sequence, as described herein with
respect to
frequency diversity.
[00154] In summary, by synchronizing the clocks of the mesh, the wireless
network is
capable of sleep cycling and frequency hopping, even without a dedicated
coordinator.
[00155] Because the mesh network 104 is sleep-cycling and frequency hopping,
it is only
operating on a given channel about once every 14 seconds and there is little
certainty
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regarding what set of channels a given wireless network is using. As a result,
it may be
difficult to join a new instrument into an existing network without
considerable delay.
[00156] The mesh network 104 solves this problem by using advertising messages
on the
public channels. Members of a network allow others to join (or re-join) a
network by
"advertising" on pre-defined public channels. New (or lost) nodes can locate
an existing
network by listening on these channels. During every network cycle, the leader
and all
followers advertise the current network parameters on both public channels
using a message,
an example of which is called boPeep().The boPeep() message may include all
information
needed to synchronize with an existing network, including synchronization of
timers, the
number of devices on the network and the identity of the frequency hopping
sequence.. New
members or members that have lost synchronization with the network may use
these network
parameters to join the network and re-synchronize with the leader. boPeep()
messages (unlike
most other wireless network messages) may be sent only with a single network
hop. This is
done to prevent flooding the network with retransmissions. Further, followers
may only send
boPeep() messages in network intervals when they have received a sync()
message from their
leader. Therefore, each follower helps identify only the current network
leader.
[00157] Referring now to Fig. 8, most routine wireless messages are broadcast
without
collision avoidance or collision detection measures enabled, which is a
byproduct of the mesh
network's 104 synchronization scheme. During a first time interval (TO to Ti),
followers
listen for the leader to broadcast a sync() message. When the sync() is
received, the followers
calculate a time for the next expected network interval. If a sync() message
is not received
and has not been received for a predetermined number of network intervals, the
node
determines that it has lost the network and begins a network rejoin sequence,
as described
below.
[00158] In embodiments, to compensate for the negative aspects of lack of
collision
avoidance or detection, the awake time during the network interval is divided
into sections
(SO, Si, S2,...,Sm) during which nodes choose a turn to broadcast to help
spread out the
network traffic over the time the network is active (thus reducing the
probability of
collisions). Messages of the highest priority, such as instrument status
messages, are sent
first during period Ti to T2. All other messages are sent after each
instrument has been given
an opportunity to send its status message (T2 to T4). Transmissions will stop,
and then a
suitable time is left to allow all messages to propagate the network (T4 to
T5). Finally, if a
sync() message was heard in that network cycle, nodes go to each public
channel and send a
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boPeep() message to advertise the network's parameters for lost nodes or new
nodes wanting
to join (T5 to T6). After T6, the node goes to sleep until the next network
interval.
[00159] In embodiments, the number of slots (SO-Sm) may be proportional to the
number of
instruments in the network (n), and when number of slots is proportional to
the number of
instruments in the network, the leader broadcasts (n) in each sync() message.
Each node
calculates the network timing and selects a slot for broadcast at random.
While this does not
guarantee a dedicated slot, this mechanism may still be effective at spreading
network traffic.
Consider also that each node's clock may be slightly out of phase with the
other nodes ¨ the
clock synchronization allows nodes to be as much as 10mS out of phase with the
leader. A
typical wireless transmission may take less than 4mS. Another key point is
that each node's
slot for broadcasting is randomly reselected on each network interval. Even if
a node
happens to transmit at the same time as another node, those two nodes are
highly unlikely to
select the same slots in the next network interval. Even with large networks,
most messages
get through and any one node is unlikely to be blocked for several back-to-
back messages.
Further, by increasing the number of slots available for transmission versus
the number of
devices in the network, the chance for collision is reduced.
[00160] In embodiments and referring to Figure 8A, the wireless network
chooses a "leader"
from the members of a network. Any node must be prepared to do the job of the
leader. In
the event that the current leader suddenly disappears, a different node
perfolins the job of the
leader. The process of picking a leader consists of nominations, elections,
and ongoing
monitoring.
[00161] In embodiments, in a first step 800, when a new node goes to the
public channel to
search for a network, it listens (such as for 4 seconds) for a boPeep()
message on a first
public channel, which indicates there is already an active leader. In a step
802, if a boPeep()
is heard, the node assumes the role of a follower of the node from which the
boPeep() was
received. In a step 804, if no boPeep() is heard, the new node switches to the
secondary
public channel and listens again (such as for 4 more seconds). If a boPeep()
is heard, the
node assumes the role of a follower of the node from which a boPeep() was
received in the
step 804. If no boPeep() is heard on either public channel, the node returns
to the primary
public channel and begins the election process in a step 806.
[00162] In embodiments, in the step 806, the node sends a nominate() message,
which may
include a leader qualification score. The leader qualification score may be
calculated based
upon instrument type, battery state of charge, and past signal quality.
Instrument type may be
a relative measure of suitability as a leader -- e.g., a fixed area monitor
makes a better leader
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than a portable instrument. These parameters determine which radio will
eventually be
selected for the leader role. As further example, instrument types with large
battery capacity
make the best leaders because leaders consume more power than followers and a
large battery
leads to less leader interruption. Some instrument types may be larger and
have greater range
due to power and antenna size. Some instruments, for example fixed area
monitors, make
good leaders because they do not move, may have higher power and are typically
located
near the center of the mesh.
[00163] In embodiments, in a step 808, the nominating node may listen for a
period of time
on a public channel, such as for 1 second. Any other node listening may
compare the
nomination message and send a concede() or nominate message depending on how
the
node's own leader qualification score compares to the nominating node's leader
qualification
score. Next, one of the following cases occurs: 1) in a step 810, if the
nominating node hears
concede() messages, but no nominate() messages, it declares itself leader by
issuing a
boPeep(); or 2) if the nominating node hears any nominate() message, it
compares the
sender(s) leader qualification score to its own and in a step 812, if the
sender's score is better,
it sends a concede() message, or 3) in a step 814, if the sender's score is
worse, it sends
another nominate() message and waits an additional period of time, such as for
1 more
second. If the qualification scores are the same, the lower MAC address is
considered better.
In a step 816, if the nominating node hears no messages after 1 second, it
sends another
nominate() message in step 806, which may be sent repeatedly, such as up to 4
more times if
the nominating node hears no message. If, after 5 seconds or a predetermined
number of
nominate() messages, for example, the nominating node has heard no messages,
it goes back
to listen on the public channels in step 800 for an additional period of time,
such as 8 more
seconds, before repeating the election process.
[00164] After being selected as the leader of a network, the leader will begin
to frequency
hop by changing the broadcast channel in each successive network interval. By
broadcasting
the boPeep() in the public channel, it will allow the nodes that lost the
election to join its
network and follow its frequency hop sequence.
[00165] In embodiments, certain area monitors on the wireless network may
continue this
process indefinitely, so that whenever a second area monitor is powered on
(and on the same
channel), they will connect automatically. Certain portable gas detectors may
be expected to
stay in this searching mode only for a limited time (e.g., minutes), before
the radio is powered
off to save power.
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[00166] In addition to synchronizing the network, the leader has a couple of
other important
jobs. One may be a process that prevents multiple leaders of a given network.
This step is
important in resolving cases where the leader becomes separated from the
network, or one
half of a network becomes separated from the other, such as when the leader
moves away
from multiple devices. In such a circumstance, the devices separated from the
leader will
nominate a new leader. However, if the two leaders come into proximity with
devices that
had previous followed a different leader, confusion can result from the
existence of two
network leaders with the same network ID. These cases can result in multiple
leaders of the
same network, which in turn can lead to erratic behavior. Therefore, it is
necessary for
leaders to occasionally stop to listen for other leaders in the network
[00167] In that regard and referring now to Fig. 9 and Fig. 10, at a regular
interval (such as
every 60 seconds), just after the network wake period ends, instead of going
to sleep the
leader remains awake (step 902) and goes to the public channels and listens
for advertising
messages to determine whether other nodes are leaders of other networks that
are in range
(step 904) . During this time, the leader intentionally skips sending a sync()
message for the
next network cycle. This causes the leader's own followers not to send
boPeep() messages in
that cycle. During this time, the leader listens for any boPeep() messages on
the public
channels. If the leader hears one, it means that there is another leader
within range operating
under the same network name. The leader relinquishes leadership and begins to
follow the
other leader (step 906). The leader's old followers (through leader health
monitoring) will
realize their leader is gone, and will also go to listen on the public
channels and will find a
new network. To maintain the leader health monitoring, a leader health counter
is maintained
and incremented by one when the leader is heard in a network interval and
decremented by
one in a network interval where the leader is not heard. When the leader
health counter
reaches zero, the node presumes that it has lost its leader and begins the
process of finding a
new leader. Therefore, this handles the difficult case where a network is
split in two. Each
half elects its own leader but is still operating under the old network name.
When these two
groups come back into range of one another, the behavior described above
causes them to be
rejoined. The new leader also sets a new awake time interval for the network
by including
the network size n = #peers+1 in the payload of the sync() message. The
leader's radio bases
the network size on the number of peer instruments reported by its instrument
software
(active or lost) plus 1 (the leader). The network size (peers + 1) is also
sent in each boPeep()
to prevent more than the allowed number of instruments from joining one
network.
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[00168] If a new leader is not elected (step 908), the leader continues in its
role as leader and
resumes sending sync() messages at the beginning of network intervals.
[00169] The leader also needs to be aware of a special situation called
"Leader of none."
Considering the case where all peers have left a network (no active or lost
peers), the leader
should not continue to operate the network without followers. Instead, the
instrument will
relinquish leadership and will return to listening on the public channels,
ready to form a new
network when another instrument is detected.
[00170] In embodiments, the wireless network may use frequency hopping, where
every
network interval occurs on a different channel, or frequency. An exemplary
process and
architecture for frequency hopping is described herein. In an embodiment, the
channels (16
channels in the case of an IEEE 802.15.4 network) may be divided between
active channels
and public channels. Preferably there are two public channels and the
remainder of available
channels are active channels. The active channels may be used in the hopping
sequence,
whereas the public channels are used for forming/joining/rejoining networks,
as described
above. Preferably, public channels will be non-adjacent and should utilize
frequencies that
are not heavily utilized (e.g., between WiFi bands, managed spectrum, etc.)
[00171] Active channels may be, by default, all channels other than the public
channels;
however, channels can be "blacklisted" by using an active channel mask. Some
active
channels may be blacklisted due to local regulations or due to high traffic
levels known to be
on the channel. For example, a wireless video camera operating on a channel
will create
heavy traffic on that channel, and therefore it may be desirable to avoid that
channel.
[00172] During operation, a different active channel may be used for each
network cycle,
called frequency hopping. The order of the hopping may be a repeating
nonrandom sequence
or a pseudorandom sequence, such as one calculated using a linear congruential
generator
(LCG).
[00173] The inputs to the generator ("hopping parameters") are a multiplier,
intercept and a
seed. At power up, each node randomly chooses a valid set of hopping
parameters and saves
them, in case it is ever called on to lead a network. In an embodiment, using
the
recommended settings with public channels 4 and 9 in a 16 channel environment,
and no
channels blacklisted, the algorithm generates hopping sequences where the next
channel is
always at least 2 channels away from the current channel (non-adjacent), if
either the public
channels or masks are modified, this may not always be the case.
[00174] When a node wins a leader election, it sends its hopping parameters
in the
advertising message (boPeep). Followers compute the sequence, using the
leader's
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parameters, and advance to the next channel, waiting to hear the leader's
sync() message.
With each network interval, the leader and all followers advance one step in
the sequence.
[00175] Leaders and followers transmit the hopping parameters on both
public
channels in the advertising message (boPeep) near the end of every network
cycle, to allow
other instruments to find the network. An instrument wanting to join a given
network, need
only listen on one of the public channels to compute the proper sequence and
next channel.
The node advances to the next channel and waits for the leader's sync()
message to begin
hopping.
[00176] The LCG calculates the next channel using the formula:
Xn+i = (aXõ + c) mod m
where X is the sequence of pseudorandom values, and
m, m> 0 the "modulus"
a, m > a> 0 the "multiplier"
c,m > c 0 the "intercept"
X0, m > X0 0 the "seed"
[00177] These values are all integers that define the sequence. In a
sequence where the
modulus is known, for example a network with 16 total channels, the modulus
may be
assumed by all of the nodes rather than transmitted in a sync() message.
Further, when a
public channel or a backlisted channel is the result of the sequence the node
can either choose
the next non-reserved channel or the next channel in the sequence.
[00178] Using wireless technology introduces certain information security
risks. The
system may include measures that prevent unauthorized listening-in to
instrument readings
and status, prevent injection of false/misleading information into a network
(like false
alarms), and prevent jamming or other denial of service attacks that would
prevent effective
use of the wireless feature set.
[00179] Wireless message contents may be encrypted by default. Encryption
means
that the contents of a wireless message are garbled and unrecognizable unless
a receiver
knows the secret password, called a "key." The wireless network may use
Advanced
Encryption Standard (AES) encryption with a 128 bit key length for messages
sent
wirelessly. This encryption is standard for the 802.15.4 radios used. These
radios may have
built-in hardware encryption engines, so using encryption has minimal impact
on throughput
or power consumption.
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[00180] Multiple approaches to wireless network security may be possible.
In one
approach, each wireless network-compatible device may leave the factory with a
default key.
The key is kept private, and it is not visible to the end user in any device
or software -- it is
embedded (and, in embodiments, hidden) within the instrument source code.
Since all
instruments have the same default key, there is no need to transmit it between
devices, just a
need to agree to use the default key. In another approach, if the user wishes,
they can enter a
customer key into their devices, using the instrument Ul, iNet, or other
maintenance tool --
again, once entered, this key is never displayed. To ensure that new
instruments can be added
to a network using a custom key, the key may be shared as part of the binding
process.
[00181] The wireless network's system of binding also helps protect from
unauthorized access to a given network. To participate in a given network, a
user first learns
the network's unique name through close contact with an instrument that is
already a member
of the group (via IR or Near-Field Communications).
[00182] Binding is the process of joining two or more wireless devices into
the same
wireless network. Implied within binding is the understanding that the devices
want to share
alarms and/or information ¨ that is, there is no network without intent to
share information.
The binding process of the present disclosure does not include the concept of
being connected
for future use. If a node is connected to the network, it is sharing and
broadcasting. No
further authentication is needed if the devices are bound to the network using
the touch
process, described further below. Anyone in the network is trusted with
allowing a new
entry. Binding is similar to the process of "pairing" used in point-to-point
networks,
including Bluetooth. However, the network 104 is a mesh network, so more often
than not,
binding is actually bringing a new device into an existing network including
several other
devices, so "pairing" is not entirely accurate because it implies only two
devices are involved.
That said, any reference to "pair" or "pairing" herein can encompass the
binding described
herein. In certain embodiments, the mesh network 104 may be established in
instruments 110
and/or 108 and/or gateways by an NFC binding process where the network
parameters are
passed and peer networks in area monitors may be established by choosing the
same named
network.
[00183] The wireless network may have multiple binding methods, such as
Named
Network and Secure Simple Binding.
[00184] Named Network is implemented in the wireless network as a list of
predefined
networks, say "A" through "J", which will be called "Channels" in this
example, though they
may have nothing to do with the frequencies used. Each wireless network-
compatible device
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may come pre-programmed for these Channels when they leave the factory.
Connecting two
devices may be as simple as making sure they are both set to the same Channel
(letter). Two
instruments set to the same Channel may connect automatically at power up if
they are within
range of one another.
[00185] With Named Networks, the selected channel is defaulted at the
factory, and
remembered through power cycles. At power up, a device may seek out and
connect to any
other devices in range and set to the same channel. Because their primary
wireless network
use case is replacement of daisy chain cables, area monitors may use Named
Network as their
primary binding mechanism. Area monitors may ship with a default network
setting and
connect "out of the box". More sophisticated users can set up different groups
of area
monitors by using different channels for different groups.
[00186] Area monitors may remember their network settings and try to
reconnect
every time they are powered up. This means that area monitors could connect
unintentionally
with an existing network. This problem should be manageable, given the smaller
number of
these devices and the generally-higher level of user expertise, instruction,
and training.
[00187] Secured Simple Binding (SSB) may be implemented in the wireless
network
by passing network "secrets" (like the PIN in Bluetooth). SSB takes advantage
of a second,
simple, short-range communications technology, called an Out-Of-Band (00B)
link, to pass
a network's credentials to a joining member. In the case of the wireless
network, an
instrument's infrared may be used (e.g. IrDA) and Near Field Communications
(NFC) for the
00B link.
[00188] Portable instruments with the wireless network compatibility may
use Simple
Secure Binding (SSB) as their primary mechanism. Near Field Communication
(NFC) may
be used for the out-of-band (00B) link. The portable binding implementation
may be biased
towards 1) preventing unintended connections and nuisance alarms, and 2) ease
of
connection. In embodiments, portables may forget their network associations at
power down.
When the instruments power up, they are in a disconnected state but are always
watching the
NFC interface for another instrument. When two portables are placed together,
they connect
to the same network, with no other user intervention required. The simple
action of touching
the instruments together ensures the connection is deliberate.
[00189] There are three scenarios to consider: 1. If neither device is
currently in a
network, the two devices may form a new network and connect.; 2. If one device
is already
participating in a network, it passes the existing network credentials to the
new instrument
and allows it to join the existing network.; and 3. If, on the other hand,
both devices are
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already part of different networks, the binding process fails and both
instruments display a
screen asking the user if they want to leave their old network. After at least
one of the users
leaves their existing network, the binding process can be repeated with
success.
[00190] Area monitors may also implement Simple Secure Binding (SSB) as a
secondary mechanism. This is a robust method for connecting any two area
monitors.
Regardless of how their configurations have been changed (custom encryption,
different
channel settings, etc.), performing SSB will arbitrate these settings so they
connect. In the
same way, a rental or replacement monitor can be added to the network without
the need for
an expert user, specialized software (e.g. ISAS software or iNET), and the
like. SSB on the
area monitor may also be used to connect a portable instrument to join into an
existing area
monitor network.
[00191] The following information may be communicated during the Secure
Simple
Binding process: Low 3-bytes of the MAC Address, Proposed Network Name, Active
Channels to be Used, Primary Public Channel, Secondary Public Channel, and
Custom
Encryption Key (if used).
[00192] Once this information is exchanged, the instruments may have all
the
information they need to complete a connection. A confirmation tone (and/or
vibratory
signal) may be emitted to indicate that the instruments no longer need to be
held together.
[00193] After two instruments exchange the binding information, they must
decide
which instrument's settings will be used in the network. If one instrument is
already part of a
network (i.e., it sent an "Allow" message), its settings are used. If neither
instrument is part
of a network, the settings of the instrument with the lower MAC address are
used, except in
the case where one instrument has custom encryption enabled and the other has
default
encryption enabled. In this case, custom encryption is considered more robust
and will be
used.
[00194] After arbitration, the instruments apply the appropriate settings
to the radio
module and attempt to connect. When the connection is successful (indicated by
receipt of at
least one other instrument's status message), a confirmation tone may sound
and the wireless
icon may be illuminated. The connection process is expected to complete within
a few
seconds.
[00195] With respect to performance, range is a function of link budget
minus path
loss. Link budget is the difference between transmitter output power
(including antenna
gain/loss) and receiver sensitivity. Output power is limited by regulations
and/or battery life,
while receive sensitivity is a function of electronics design quality and data
rate.
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[00196] Shown below is the free-space path loss equation that predicts
range (d) of a
RF signal.
II4Ar .P,;
- PI tV:the trentriiittea power. Or is the receNed, POMO'.
¨ Pi, is the transmitter. Gf IS the receiver antenna gain
¨ ,d. is the distance between transmitter and receiver4. bribe; range
¨ Lambda ia-the wavelength
I
Eqn. 1
[00197] Using a radio module as example: Pt = 3dbm; Pr = -100dbm; and d =
250m,
including a conservative fade margin of 15db. Fade margin captures the
practical sensitivity
of the receiver, and includes antenna polarization, reflections, multi-path
interference, etc. A
fade margin of 6dB would represent ideal conditions (clear weather, antennas
aligned, etc.); a
more conservative number might be 15dB.
[00198] Practical range in an industrial setting is different from a free-
space
environment. Through a typical warehouse environment, actual range for the
radio modules
may be about 75m. Line of site through a large factory may be approximately
100m. Actual
range may vary widely depending on the environment, and the mesh topology
extends the
effective range dramatically. Height off the ground may also impact range.
[00199] In embodiments, the mesh network 104 may be designed to operate
with
between 2 and 25 instruments in a given network. If there are too few nodes
for an
environment, the network may not have enough paths to be effective. When
networks grow
too large, the individual nodes have to compete for the shared resource of
network
bandwidth. Therefore, in embodiments, the optimum network size is typically
between 8 and
15 instruments.
[00200] Because of the frequency hopping and the short transmission time of
802.15.4
radios, hundreds of instruments can operate within the same area without
interference,
provided they are operating on different networks, as described herein. The
discussion herein
with respect to joining/re-joining a network provides details on how network
size is
controlled.
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[00201] Hardware enabling wireless network-compatibility may include: An
802.15.4
Radio system on a chip ("SoC"), supported by a network operating system
(typically a pre-
certified module); memory IC and circuitry that implements a shared memory
interface; and a
precision timer used to maintain network synchronization. In some embodiments,
a
barometer may also be included.
[00202] Hardware enabling wireless network-compatibility may be implemented
directly on the portable gas detecting instrument mainboard. For models of the
portable gas
detecting instrument without wireless functionality, these parts are
depopulated. In other
embodiments, such as for area monitors, the hardware enabling wireless network-
compatibility may be implemented in a pluggable PCB (module), such as for area
monitors.
The module may also add a GPS receiver (which may or may not be populated).
While not
technically part of the feature set, the GPS feature may be implemented as
part of the script
running on the Radio SoC. Although a slightly different radio module may be
used on area
monitors, the other circuitry may be identical to the hardware implementation
for portable
instruments (other than GPS).
[00203] Fig. 11 depicts the wireless network architecture. In Fig. 11, the
structure of
two instruments 108, 110 with radio modules that interact in a wireless mesh
network is
depicted. Each of the instruments are depicted as being similar, but the
instruments may be
different instruments, and their structures may be that of a portable device,
area monitor, or
the like. Each instrument may have one or more end applications, such as gas
detection, peer
alarms, shadow gas, and the like. Each instrument may be involved in network
management,
such as with activities such as peer instrument list, signal quality,
connect/disconnect,
identify, and the like. An instrument-radio interface 1114 (e.g. serial,
digital I/O) is shown
operating to connect the instrument application component with the radio
module 1118 and
its wireless network protocol. A wireless interface 1120, the wireless mesh
network, is
shown between the radio modules 1118. Fig. 13 depicts the wireless network
fitting in a 7-
layer OSI Model.
[00204] In embodiments, the same wireless radio useful in the wireless
network may
be used in a master-slave relationship between an instrument and its
accessory. In this case,
each accessory device would include a similar radio as the instrument.
Possible accessories
include auxiliary alarm devices, smart sample draw pumps, or even a bridge to
a smartphone
or other mobile gateway or computing device. The bridge would communicate with
the
instrument using the wireless network technology but convert communications to
another
format. The other format could be Bluetooth to connect to a smartphone 118, or
an industrial
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protocol like HART or WirelessHART, or WiFi. Accessories could also include
additional
sensing devices (gas, workers vital signs, or otherwise) that would share the
display, datalog,
and alarms already found in the gas detector. Another example is an adapter
that holds an
inline benzene filter, and communicates with the instrument to indicate filter
state
(engaged/bypassed) or filter age.
[00205] In certain embodiments, the parts of a gas detector (sensor,
display, alarm,
etc.) may actually be separate devices, connected wirelessly. With this model,
a sensor could
communicate with a smartphone 118.
[00206] Fig. 12 depicts how the hardware enabling wireless network-
compatibility can
be extended to a platform using gateways 112 to the Internet for the end
application of remote
monitoring and the like. For example, the gateway device 112 may receive data
from an
instrument 108, 110 through the mesh network 104 and transmit it to the cloud
via cell, Wi-
Fi, Ethernet, or satellite. The gateway device 112 may be intrinsically safe,
extended battery
power (such as 7 days), rugged, and wall-mountable or transportable. Fig. 12
depicts an
instrument 108, 110 structure similar to the ones shown in Fig. 11, but the
instrument 108,
110 is in communication with a gateway 112 in this instance via a wireless
mesh network,
such as the mesh network 104. The gateway 112 may include a radio module 1118
with a
serial connection to a single-board computer 1214. The single-board computer
1214 may
include a gateway application 1218 that is in communication with a database,
and with a
network through a communications protocol, such as the interne, Ethernet,
cellular, WiFi,
satellite, and the like. The network may ultimately allow an end user to
connect to the
worker safety system with a PC/mobile device 1220. The gateway 112 is shown in
Fig. 1
where wireless network-compatibility is extended to a platform using gateways
112 to the
Internet. Data may be transmitted between devices using the mesh network 104
and data may
be transmitted to the gateway 112 using the mesh network 104. The gateway 112
may
transmit data to the cloud via cellular technology, WiFi, and/or satellite
where it may be used
in a variety of applications as further described herein. For example, when a
gas detector
goes into alarm and the data are transmitted back to the cloud, a remotely
located supervisor
may deploy a response team, send a message back to the gas detector, call the
worker with
the gas detector on a separate phone or on the gas detector itself if it
possesses
telecommunications functionality, ask another nearby worker to check in on the
worker, and
the like. Data may be aggregated over time regarding alarms and other safety-
related data to
identify risks or safety-related issues in an area, as is described herein.
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[00207] With continuing reference to Fig. 1, data may be transferred from
the
instruments 108, 110 to other devices, such as mobile devices, tablet
computers, local
computers, beacons, and the like using communications protocols such as NFC,
Bluetooth
and the like. In an illustrative example such as that depicted in Fig. 1, an
API 114 may be
used to transfer data between the instruments 108, 110 and smart devices 118/
mobile
gateways 131, wherein the smart devices may use the data itself or transmit
the data on to a
remote server 130 or the cloud via WiFi, cellular, satellite or the like. In
some embodiments,
the instruments 108, 110 may transmit data directly to a remote location, such
as by having
integrated WiFi, cellular or satellite technology. There may be two-way
communication
through the device 118 or mobile gateway 131 such that remote computers or
applications
running in the cloud may be used to control, configure or otherwise
communicate with the
instruments 108, 110 through the device 118 or mobile gateway 131. For
example, a report
from a gas detector or a group of gas detectors that a gas threshold has been
reached may be
sent to a remotely located supervisor. The supervisor may be enabled to take
many actions
through the worker safety system, such as communicate back to the instrument,
change the
display on real-time signage, take control of a local device, such as a drone-
mounted gas
detector or camera, and the like. In embodiments, the worker safety system may
automatically take control of local devices or instruments based on a report
from an
instrument.
[00208] Referring now to Fig. 3, a plurality of portable environmental
sensing devices
108, 110 in a work area adapted to communicate with one another in a mesh
network 104 are
shown. In Fig. 3, some devices 108, 110 are shown in communication with a
remote server
130 or computer via a communications facility, such as a dock 122, gateway
112, mobile
gateway 131, or smart phone 118. Other devices in the mesh network 104 may not
be in
direct communication with the remote server 130 or computer and instead rely
on receiving
data or instructions through the mesh network 104 from other devices 108, 110
that are in
communication with remote servers 130 and computers. The communications
facility
transmits data from at least one of the plurality of portable environmental
sensing devices to a
remote computer, wherein the remote computer is configured to monitor at least
one of a
hazardous condition and an activation of a panic button in the work area based
on data from
the at least one of the plurality of portable environmental sensing devices.
The remote
computer is configured to receive, from the at least one portable
environmental sensing
device, an alarm related to the hazardous condition or activation of panic
button, and transmit
to any of the portable environmental sensing devices an instruction to be
propagated
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throughout the mesh network. The instruction may be a request to check the
safety of a user
of the at least one portable environmental sensing device, an evacuation
instruction, a risk
mitigation instruction, and the like. The remote computer may further be
configured to
display the location of the portable environmental sensing devices in a map of
the work area
and transmit the map for display on any of the portable environmental sensing
devices. The
data transmitted by the communications facility can be sensed gas data,
wherein the
hazardous condition is based on the sensed gas data exceeding a threshold. The
remote
computer may be further configured to display the sensed gas data in a map of
the work area,
wherein a size of the representation of the gas data is proportional to the
gas level. The
remote computer may be further configured to request an emergency response at
the location
of the at least one portable environmental sensing device.
[00209] In an illustrative example, applications resident on the smart
device may send
data to the cloud. Applications served by a cloud or other remote server 130
may receive
data sent by smart devices or from the gateway 112 and provide web interfaces
for various
end use applications, such as monitoring, mapping workers and alarms/events,
notifications,
alarms, e-permitting, compliance, emergency response, safety inspections,
accountability,
risk management, compliance, lone worker solutions, worker networks, 3" party
integration,
device/instrument control, and the like, as will be described further herein.
[00210] Continuing with Fig. 1, the instrument 108 is depicted as in
communication
with a beacon 102. The beacon 102 allows for broadcasting information to the
instrument
108. In embodiments, the data broadcast by the beacon 102 may be stored by the
instrument
108.
[00211] Fig. 1 also depicts an NFC tag in relationship to the instrument 108
and thus other
components of the system. For example, data collected by the instrument 108
from the NFC
tag may be used to tag gas detection data to enable quickly identifying the
gas detection
instrument operator and location to make the gas detection information more
actionable.
[00212] Gas detection instruments, portable environmental sensing devices, and
other safety
devices with integral technology that collects temporary assignment and
location information
may enable valuable insight into gas exposure data, safety events and user
behavior, while
being useful when managing assets and investigating potential issues. Tagging
gas detection
data and other collected data allows anyone reviewing the data to easily see
who had the
instrument and where the operator was using it, making the information more
actionable.
This disclosure may refer to gas detection instruments and area monitors in
the description
and examples of the systems and methods. Such references are meant to apply to
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components of the system described herein, such as environmental sensing
device 108, area
monitor 110, gateway 112, API 114/ Smart Device 118 or mobile gateway 131, it
should be
understood that other environmental sensing devices, area monitors, and
components may be
used with the embodiments described below.
[00213] NFC tags are short range, small, non-powered tags with a small memory
and a radio
chip attached to an antenna. Having no power source, they draw power from the
device that
reads them, thanks to magnetic induction. When a reader gets close enough to a
tag, it
energizes it and transfers data from that tag. The assignment tag may be
small, light, require
no battery, and may withstand harsh outdoor environments. Assignment tags may
be in
multiple styles, such as a sticker tag, a waterproof sticker tag, an outdoor
tag, a keychain tag,
and the like. The assignment tags may be continually overwritten as needed or
locked so that
they cannot be reprogrammed.
[00214] The gas detection instruments with NFC technology may support multiple
assignment types, such as recurring and temporary assignments. A recurring
assignment may
persist with the instrument when the instrument is restarted. A recurring
assignment may be
made using an application or software, such as iNet Control, DSSAC (Docking
Station
Software Admin Console), or accessory software resident on the instrument or
other
component of the system that communicates with the instrument. A temporary
assignment
may be made via an application or through the instrument settings. Temporary
assignments
may overwrite recurring assignments and stay with the instrument until it is
restarted. Upon
restart, an instrument with a temporary assignment may revert to the recurring
assignment, if
one is available. If there is no recurring assignment, the instrument may be
unassigned.
Alternatively, to remove a temporary assignment, the assignment tag may be re-
touched to
the instrument when the assignment is no longer needed.
[00215] In an embodiment, and referring to Fig. 14, in order to make use of
the NFC
assignment capabilities of the gas detection instrument, assignment tags 1402
may be
programmed with an assignment using an assignment application 1404 or other
assignment
software. The tags may need to only be programmed once. The tags may then be
distributed
to instrument operators or installed at a location. Then, instrument users may
touch the gas
detection instrument 108 to an assignment tag so that the NFC radio in the
instrument may
sense the assignment tag.
[00216] Assignment tags for identifying individuals may be programmed with a
variety of
identification data, such as name, size and weight (such as to be able to
calculate a person-
specific gas hazard threshold), typical work locations, job function, security
and or
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authorization information which may include whether the user is authorized to
use a specific
instrument or be in a specific location, typical instruments used by the user,
pre-existing
events caused or experienced by the user such as prior alarms or gas events,
languages known
by the user, prior alarms, and the like. Assignment tags for identifying
locations may be
programmed with a variety of data, such as location within a space, GPS
location, equipment
at the location, fuel sources at the location, known hazards at the location,
typical gas
concentrations for the location, other environmental conditions for the
location, recent gas
events at the location, recent man down alarms triggered at the location,
recent alarms
triggered at the location, recent messages triggered at the location, and the
like.
[00217] Referring now to Fig. 15, as described herein the worker or industrial
safety
monitoring system may include a personal NFC tag 1502 assigned to a worker,
wherein the
tag assigned to the worker comprises identity information of the worker, such
as name, size,
weight, job title/function, company, languages spoken,
certifications/licenses,
accommodations, approved tasks, approved locations, approved equipment, hours
worked,
typical work location, a typical instrument/equipment used, a pre-existing
concern, a prior
alarm, a prior gas or safety event, any prior radiation exposure levels, a
prior message, a
security clearance, and the like.
[00218] NFC assignment tags 1502 may be carried by workers or attached to a
name badge,
employee ID, hardhat, tool belt, or other personal item. The system may also
include and/or
interact with a plurality of location NFC tags 1504 assigned to locations,
each location tag
placed in a location comprising information of the location in which the
location tag is
placed. Certain parameters associated with the location may be programmed into
the NFC
tag, such as for example, location name, latitude/longitude/GPS coordinates,
typical
temperature, typical humidity, a level of authorization needed to
enter/service the location,
the type of equipment in the location, a certification/license needed to
operate equipment at
the location, personal protection or safety gear required, instructions to be
followed,
instructions for on-site equipment, gas detection instrument dock nearby, a
fuel source at the
location, a known hazard at the location, a typical gas concentration for the
location, an
environmental condition for the location, a recent gas event, a recent man
down alarm, a
recent alarm, a recent message, and the like.
[00219] A portable environmental sensing device 1508 detecting data of an
environmental
parameter may be configured to (i) read the personal NFC tag and store the
identity
information of the worker using the sensing device, (ii) read at least one of
the plurality of
location NFC tags and store the information of the location of a location tag
read by the at
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least one portable environmental sensing device, (iii) associate the location
information,
identification information, and/or any parameters detected by the sensing
device and store
such associated information, and (iv) transmit any of the information above to
other
components of the system. Note that the transmission of data may be
accomplished in
accordance with the methods described herein, such as via a P2P network, mesh
network
and/or to and through the cloud in manners described herein. Components
receiving and
operating on the data may be as described herein. In accordance with the
description herein
at least one processor 1510, which for example may be located in another
instrument 108/110
or part of the remote server 130, may be in communication with the at least
one portable
environmental sensing device 1508 and may receive any of the information above
(i)-(iv)
from the at least one portable environmental sensing device 1508. In
embodiments, the at
least one processor 1510, itself, may be programmed to determine an
environmental
parameter of the worker using the sensing device 1508 and the location of the
determined
environmental parameter based on the data it received from sensing device
1508. The system
may further include a remote server 1512 comprising a memory 1514 in
communication with
the at least one portable environmental sensing device 1508 that stores the
detected data and
the information in a data log. The system may further include a wireless
transmitter 1514
that transmits, including in the manners described herein, the detected data
and the
information to a cloud-based or other remote server 130 or log. The
transmitter may be the
gateway 112, API 114/Smart Device 118 or mobile gateway 131 as described
herein in
connection with Fig. 1. In embodiments, the wireless transmitter 1514
transmits the detected
data and the information to another portable environmental sensing device 1508
or other
safety device. For example, a detected event on a first portable environmental
sensing device
may be transmitted to one or more other portable environmental sensing
devices, gas
detection instruments, safety devices, servers, computers, smartphones, and
the like in the
form of a message, an alert, or raw data, wherein the transmission may include
the
information derived from the NFC tags.
[00220] In an aspect, workers may wirelessly enter a name and a location into
the device
1508 or instrument 108/110 simply by tapping the NFC assignment tag to the
instrument.
Alternatively, location information may be automatically collected via GPS or
other location
sensing technology. Once the user and/or site information has been transferred
from the
assignment tag to the instrument, data recorded by the device 1508 or
instrument 108/110
may be tagged with the user and location information and saved, in the
instrument data log or
wirelessly transmitted to a cloud-based or other remote server 130.
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[00221] In another example, each employee may receive his or her own
assignment tag
identifying them which can be attached to a name badge, employee ID, or other
personal
item. Then, each day, the employee may pick up an instrument from a shared
pool or tool
crib, wherein the instruments may be compliant, calibrated, and/or bump-
tested, at the start of
his or her shift. When the instrument is touched to the assignment tag, the
assignment is
complete. The device may be further configured to the user's needs and/or
specification, and
may also include data about the user. This may be an example of a temporary
assignment. In
another example of a temporary assignment, the assignment application may be
used to
assign the location "Tank 1" to an assignment tag. The tag can then be
installed at the
entrance to Tank 1. When instrument operators enter Tank 1, they can touch
their instruments
to the tag and the location assignment will be saved to the instrument. These
examples may
describe separate scenarios or a single scenario. For example, the instrument
operator may
temporarily assign themselves an instrument from the tool crib, then assign
the 'Tank 1'
location upon arrival to Tank 1. Thus, data will be tagged with both the user
identification
and the location at which other data are collected.
[00222] In embodiments, using NFC tags, a permission-based perimeter fence may
be
established. For example, if only certain users are allowed to enter 'Tank 1',
only those users
may be able to assign the 'Tank 1' location to their instrument, which may
then be used for
electronic entry to 'Tank 1', for example.
[00223] In embodiments, the system of Fig. 15 includes a beacon 102, which
may
repeatedly transmit an informational message, the beacon's payload.
[00224] In embodiments, customized on-screen messages may be provided to the
gas
detection instrument with specific information or instructions, such as
instructional text to
assist users in knowing how to react properly in the event that an instrument
alarm occurs.
The messages may be programmed into the instrument itself or any system
component in
communication with the instrument and automatically triggered, such as through
detection of
one or more particular gases or detection of a threshold amount of gas. In
other
embodiments, the messages may be manually delivered, such as from a
supervisor, another
instrument user, a facility manager, an instrument manager, a control center,
or the like.
Certain messages may display during the instrument start-up sequence. Certain
messages
may display during gas or other safety events. In embodiments, a unique
instructional
message may be set for each of these events for each sensor: gas present
(alert, low alarm,
and high alarm), STEL (short-term exposure limit), and TWA (time-weighted
average). For
example, an alarm action message may be programmed for each all alert/alarm
set points for
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each sensor of the gas detection instrument to tell the user, in their native
language, whether
they should wear a respirator, leave the area, seek shelter or take whatever
action is dictated
by the company emergency response plan. Alarm action messages mean that an
instrument
user need not be trained to interpret and understand the meaning of all gas
readings, rather the
user simply need to read the display and heed the instructions. Alarm action
messages may
change based on assigned user or location.
[00225] In embodiments, the gas detection instrument may feature audible,
visual, and/or
vibrating alarm indicators that may be used in multiple modes. For example,
the audible
indicator may be capable of delivering a tone at a programmed decibel level,
in embodiments,
95dB, at a pre-set distance. In another embodiment, output could be visual
such the flashing
action of four ultra-bright LEDs, of varying colors such as red and two blue,
may attract the
attention of the user and others around. In yet another embodiment, a
vibrating alarm may
provide a tactile alert to the user in the highest noise environments.
[00226] In embodiments, the device 1508 or instrument 108/110 may execute an
application
that is programmed to utilize the assignment data, such as user identification
and location or
other information programmed to the assignment tag, to trigger alarms and/or
messages, or
filter the triggers. The application may be updated periodically by the server
130, such as to
modify variables that will cause a trigger at particular locations or
relationships concerning
worker variables and alarm triggers. For example, at one particular location,
detection of a
particular gas may not be cause for alarm, however, at another location where
conditions may
be different, the same gas at the same detected concentration may be
concerning or
dangerous. For example, methane detected at a particular level may trigger an
alarm and/or
message at a location where ignition sources are present but cause no triggers
at locations
where it is known that no ignition sources are present. In another example,
the gas detection
instrument may only trigger a high carbon monoxide alarm if the user assigned
is above a
certain weight.
[00227] As discussed herein, data transmitted through the gateway 112 or a
device to a
remote location may be used in various end applications either by itself or in
conjunction
with other data, other devices, other information or the like. Any number of
applications of
the worker safety system may be imagined, a number of exemplary applications
will be
described herein.
[00228] In one example, data from instruments 108, 110 or other nodes may be
used for
continuous safety inspections. Limits for particular measured variables may be
set for
individuals and/or groups in respect of automated, real-time, monitoring of
safety parameters.
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The worker safety system may issue warnings when limits are approached to the
appropriate
audience.
[00229] In one example, data from instruments 108, 110 or other nodes may be
used for lone
worker monitoring. For example, if a lone worker's device triggers an alarm,
such as a gas
alarm, the connectivity of the instrument to a smart device, such as via an
API 114, allows for
that alarm to be detected remotely. Remote detection of an alarm may allow a
supervisor, for
example, to check-in on the lone worker or be able to send help as needed.
[00230] In an example, data transmitted to the cloud from instruments 108, 110
may be
used for e-permitting. Certain confined spaces cannot be entered without first
sampling the
environment in the confined space, thus a sampling device may need to be
present.
Typically, permitting to enter the confined space is done using manual data
entry to apply for
a permit. The disclosure herein enables the same device that collects data on
the environment
of the confined space to transmit that data to an electronic permitting
application for use in
applying for a permit to enter the confined space. In embodiments, the device
118 may be a
ruggedized tablet with an integrated gas sensor or with a connection to an
instrument 108,
110 that provides gas sensing, wherein the sensed data are automatically
provided to auto-fill
an onboard application or transmitted to the cloud for use in an application,
and in
embodiments, is auto-submitted to the relevant permitting authorities.
[00231] In an example, data transmitted to the cloud from instruments 108, 110
may be
coordinated with third party data. For example, additional hazards may be
alarmed through
the instruments 108, 110 by overlaying location data derived from the devices
118 or
instruments 108, 110 with third party data, such as NOAA data,
news/threat/terrorist data, or
other external/3rd party data. Such a capability may be especially important
for lone workers.
[00232] In an example, data transmitted to the cloud from instruments 108, 110
may be used
by fire responders and other first responders. In addition to SCBA data, data
from
environmental monitoring (e.g. gas data), can be delivered automatically to
fire responders
(or other first responders) to provide site/all-in-one safety. The worker
safety system may
support automatically configured emergency nodes for first responders. For
example,
automatic configuration / pairing may occur for emergency responder use in a
monitoring
group. In embodiments, separate indicators may be used for responder-worn
nodes
[00233] In an example, data transmitted to the cloud from instruments 108, 110
and various
safety devices may be used by the worker safety system in the personal
monitoring of various
physiological and/or behavioral attributes of an individual in order to obtain
information
relevant to workplace safety, or to alert nearby users regarding a workplace
safety situation.
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Thus, the worker safety system provides a remote and local biometric
monitoring interface
with nodes in the ad-hoc P2P or mesh network. A user-worn node has an
interface to a
worker to monitor physiological and/or behavioral attributes. The measured
biometric levels
are used for remote monitoring and alarms. The goal of such monitoring may be
to
determine the root causes and acute symptoms of death and injury in the
workplace and
mitigate the risk of death in the workplace or other major accidents and
exposures, such as
injury from fires or explosions, exposure to harmful substances or
environments, falls, slips,
trips, contact with objects and equipment, assaults and violent acts, suicide,
terrorism,
transportation incidents, overexertion, repetitive motion, and the like. A
further goal may be
to detemtine and understand the physiological and behavioral effects of the
root causes and
acute symptoms of death and injury in the workplace. The worker safety system
may be
useful in various industries, such as in mines, diesel/fuel plants,
refrigeration, fertilizer plants,
food & beverage, firefighting, chemical processing & manufacture, HazMat,
medical, law
enforcement, insurance, and the like.
[00234] Illustrative physiological markers may include ECG, heart rate,
breathing rate, skin
temperature, posture, activity, accelerometry, blood pressure, pulse, body
odors, blood
alcohol level, glucose levels, oxygen saturation, and the like. Illustrative
behavioral markers
may include gait, walking patterns, eye movements, motion patterns, noises,
removal of the
sensor from the person before a prescribed time, and the like.
[00235] Physiological and/or behavioral attributes may be measured by sensors,
such as
sensors integrated with instruments 108, 110, sensors located on the body of
an individual,
clothing, and/or devices worn or used by the individual. In embodiments,
various sensors
may be used to measure a person's physiology and behavior, such as one or more
of heart
rate sensors, blood pressure sensors, gait detection sensors, olfactory
sensors, galvanic skin
response sensors, proximity sensors, accelerometers, eye tracking sensors,
cameras/image
sensor, microphones, infrared sensors, gas sensor, capacitive sensor,
fingerprint sensor, signal
detectors (e.g. WiFi, Bluetooth, mobile phone, etc.), location detectors (e.g.
GPS sensor), and
the like.
[00236] The physiological and/or behavioral attribute information may be used
to gain
insight into the characteristics of an individual, a department, or a category
of employee that
may have an effect on the safety and working conditions thereof. For example,
the worker
safety system may obtain data for an individual to obtain a day-to-day
baseline and may
compare current information to the baseline information. In another example,
the worker
safety system may compare an individual's information with a pool of data or
with co-
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workers in a similar situation. The worker safety system may obtain and
analyze the
physiological and/or behavioral data to determine the physiological state of
an individual
(e.g., under stress, fatigued, etc.), the causes of accidents in the
workplace, or to make
predictions about workplace accidents. The worker safety system may utilize
sensed data and
algorithmic output to provide intervention to the individual or other
interested parties (e.g.
after two "near misses", a supervisor is alerted and re-training may be
scheduled), to block a
user from being able to access certain systems (e.g. after detecting a change
in gait coupled
with a temperature change, a signal is sent to nearby heavy machinery to block
access to the
individual), to allow a user to access systems (e.g. this individual was
blocked because of flu
but their temperature is now normal), to suggest behavioral changes to avoid
an accident (e.g.
after eye tracking indicates fatigue, the user is signaled with a suggestion
to take a break), and
the like. The collected data may go into a pool of data that can be used for
subsequent
comparisons.
[00237] The worker safety system may use the human body, such as human
physiology and
human behaviors, as a safety sensor or monitor to detect hazards including
various sensors to
measure a person's physiology and behavior, and then make use of data from a
person or
group of people, both physiological and behavioral, of data algorithms to
identify a safety
issue, and of the data from a person or group of people to prevent accidents
or fatalities using
certain physiological or behavioral markers. In embodiments, sensors deployed
to obtain
human physiology and human behaviors may form a body area network.
[00238] In embodiments, the use of data from a person or group of people, both
physiological and behavioral, may be used to predict an accident, workplace
injury, incident,
"near miss", etc.; determine if a person is in danger; determine if the
environment is
hazardous; identify the hazard or family of hazards; make judgments about the
safety of a
person, group of people or the environment; alert the person, group of people
or someone
who will intervene via visual, audible, haptic alarms and the like; determine
if the person is at
risk of a future accident (including the use of near miss data); look for
known patterns or to
identify new patterns related to personal safety, and the like.
[00239] In embodiments, the use of data algorithms may be used in the
following ways to
identify a safety issue: compare a person against themselves in near time or
in historical time;
compare the person against the data from a population; compare the data from
one person to
others working with them at that point in time, and the like.
[00240] In embodiments, use of the data from a person or group of people may
be used to
prevent accidents or fatalities using physiological or behavioral markers. For
example, at
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least one of heart rate, eyelid closures, pupil size, blood pressure, posture,
jaw drop, breathing
rate, ECG, skin temperature, and sweat may be used as markers to prevent
accidents or
fatalities in the field of transportation. In another example, at least one of
gait, acceleration,
blood pressure, heart rate, breathing rate, and posture may be used as markers
to prevent
accidents or fatalities in the field of contacts with objects or equipment. In
another example,
at least one of gait, acceleration, blood pressure, heart rate, breathing
rate, posture, ECG,
sweat, and skin temperature may be used as markers to prevent accidents or
fatalities in the
field of slips, trips or falls. In another example, at least one of gait,
acceleration, blood
pressure, heart rate, breathing rate, posture, ECG, sweat, and skin
temperature may be used as
markers to prevent accidents or fatalities in the field of exposure to harmful
substances. In
yet another example, at least one of blood pressure, heart rate, breathing
rate, posture, ECG,
sweat, and skin temperature may be used as markers to prevent accidents or
fatalities in the
field of assaults or violence. In still another example, at least one of gait,
acceleration, blood
pressure, heart rate, breathing rate, posture, ECG, sweat, and skin
temperature may be used as
markers to prevent accidents or fatalities in the field of fires or
explosions.
[00241] In embodiments, a database of sensor readings may be used to determine
the
appropriate prediction or identification of the safety issues and the
appropriate response. The
sensor readings may be wirelessly transmitted to a computer, instrument
108/110, or device
118 and processed in near real time or real time to provide infonnation and
insight regarding
safety and hazard issues. The database may be consulted for matching sensor
readings and
matching combinations of sensor readings. Each combination of sensor readings
may be
associated with one or more particular safety issues and may be associated
with one or more
particular responses. The safety issue and/or response may be further limited
by an
additional factor, such as a supervisor or administrator preference, a
facility preference, a
location, a user, a context, a season, or a business rule. In an aspect, a
method of the
disclosure may include obtaining sensor data from one or more physiological
and behavioral
sensors worn by a user 1602, analyzing the sensor data to identify a safety
issue 1604, and
providing an alert to the user or an interested party regarding the identified
safety issue 1608.
Analyzing may include matching the sensor data to a known combination of
sensor readings
in a database of sensor reading combinations. In an embodiment, an application
resident on
the instrument 108/110 or device 118 may determine a condition hazardous to
safety based
on the sensor readings and algorithms to determine if the readings are
indicating of a root
cause or acute symptom of an incident. If a root cause or acute symptom is
identified, an
alert may be generated and sent through the instrument/device via the wireless
network 104
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to alert other users and ultimately on to the server 130. In embodiments, the
transmitted
information may be used to de-authorize the user from an area or equipment,
deploy
personnel, remotely close off an area, request a check-in on the user, and the
like.
[00242] In embodiments, when certain physiological markers are combined with
certain
behavioral markers in a known pattern, a condition may be determined and an
alert or
response may be elicited. In one example, when a person falls or almost falls,
physiological
markers of the condition may include the heart speeding up, blood pressure
rising, sweating,
lungs breathing faster, and the temperature in the extremities may decrease.
Behavioral
markers of the condition may include a noise being made, a sudden acceleration
then a period
of not moving, and the like. These markers taken together may form a pattern
indicative of a
fall or an almost fall.
[00243] In another example, when an individual is sleep-deprived,
physiological markers of
the condition may include increased heart rate, increased blood pressure, and
reduced leptin
levels. Behavioral markers of the condition may include increased eyelid
closure, eyes
rolling, and yawning.
[00244] Table 1 indicates various incidents and their possible root causes or
acute
symptoms. When text is present in the cell, it is an indication that there is
a correlation
between the incident and the possible root cause or acute symptom. In some
embodiments,
there may be a temporal aspect to the correlation, such as if the root cause
or symptom can be
measured prior to the incident (Before), after the incident (After), or both
(Both). In some
instances, a simple correlation (Correlated) is indicated. The cells in Table
1 are blank if no
correlation is currently known.
Table 1. Root Causes or Acute Symptoms of Incidents
Root Causes or Transportation Violence Contact
with Falls, Exposure to Fires and
Acute Objects/Equipment Slips, Harmful
Explosions
Symptoms Trips Substances/
Environments
Acute Stress Both Both
Fatigue Before
Under influence Both Correlate Both
(Drugs/Alcohol)
Distracted Before Correlated
Excessive Before
Speed
Equipment Correlated
Failure
Weather Correlated Before Before
Aggressive Correlated
Anger Both
Fear After After
Awkward Gait Both
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Root Causes or Transportation Violence Contact
with Falls, Exposure to Fires and
Acute Objects/Equipment Slips, Harmful
Explosions
Symptoms Trips Substances/
Environments
-Injury Before
Old age Both
Inadequate Before
traction
Speed of Before
movement
Light/Dark Before Before
Temperature Before Before
[00245] With respect to fatigue, markers including heart rate, blood pressure,
eyelid closures
(slow closures, frequency of closures), pupil size, head position, and jaw
drop, as well as
other cardiovascular disturbances and sympathetic activity may be used to
identify the
condition.
[00246] With respect to stress, markers including heart rate (e.g. increased
heart rate), sweat,
dilated pupils, shallow breathing, increased blood pressure, changes in a
person's voice
(pitch, rate, volume), odor and tightened scalp may be used to identify the
condition.
[00247] With respect to being under the influence, markers including breathing
rate,
increased blood pressure, increased heart rate, gait and speech changes may be
used to
identify the condition.
[00248] With respect to anger, markers including jaw clenching / teeth
grinding, headache,
stomachache, increased blood pressure, increased breathing rate, increased
heart rate,
sweating (especially hands), feeling hot in the neck/face, shaking /
trembling, and dizziness
may be used to identify the condition.
[00249] With respect to slips, trips, and falls, markers including breathing
rate, blood
pressure, heart rate, and awkward gait may be used to predict or identify a
slip, trip, or fall.
For example, the pattern for fear of heights, which is an indicator of
potential falls, may be
heart rate increase, stress temperature decrease, and systolic BP increase.
However, if the
situation includes an activity, such as climbing a ladder which might increase
the heart rate
independently, then adding a gait measurement may be necessary to determine if
the
individual is in motion or not.
[00250] With respect to carbon monoxide exposure, markers including nausea,
vomiting,
restlessness, euphoria, fast heart rate, low blood pressure, cardiac
arrhythmia, delirium
hallucinations, dizziness, unsteady gait/stumbling, confusion, seizures,
central nervous
system depression, unconsciousness, respiratory rate changes, and respiratory
arrest may be
used to identify the condition.
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[00251] Table 2 depicts how various physiological markers are associated with
particular
root causes or symptoms.
Table 2, Part 1. Physiological Markers of Root Causes or symptoms.
Root Causes Heart Blood Sweat Breathing Gait Pupil
Size Shaking/ Dizzy
or Acute Rate Pressure Rate Change Trembling
Symptoms
-
Acute Stress X X X X X X X .
Fatigue X X , X , X , X
, . , '
Under X X X X X X X
influence
(Drugs/Alcoh
ol) ,
Distracted
Excessive
Speed _
' .
- Equipment
Failure ,
Weather X X , X , X
, , ,
' . ,
Aggressive ,
Anger X X X X X X
Fear X X X X X
. ,
Awkward X X
Gait
Injury X
Old age X
Inadequate X
traction ,
- _
Speed of X
I I I
movement
Table 2, Part 2. Physiological Markers of Root Causes or symptoms.
Root Causes Stomach Head Hot/flushed Body 02 Odor Eye Head
Voice
or Acute ache ache face & Temp Level Blinks
position, changes
Symptoms neck facial
changes, jaw
, drop
Acute Stress X
Fatigue X X X , X X
, . .
Under X ' X X
influence
(Drugs/Alcoh
ol)
Distracted
Excessive I I I
Speed .
Equipment
Failure
Weather X X X . . .
Aggressive , _ _ .
Anger X X X
Fear X X
_
Awkward
Gait
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Root Causes Stomach Head Hot/flushed Body 02 Odor Eye Head
Voice
or Acute ache ache face & Temp Level Blinks
position, changes
Symptoms neck facial
changes, jaw
drop
Injury
Old age
Inadequate
traction
Speed of
movement
[00252] In embodiments, the systems and methods for monitoring physiology and
behavior
to identify or predict safety issues and mitigate risk may be embodied in a
wearable device.
In embodiments, the wearable device may include multiple physiological or
behavioral
sensors, such as those described herein. In embodiments, the wearable device
may be a
garment with one or more embedded sensors, a watch, a portable device, a
badge, eyewear, a
ring, and the like. The wearable device may include a wireless transmitter to
transmit data in
the manners described herein and ultimately to a server for analysis. The
device may include
a display to present content from a server based on analyzed data. The content
may be
information or an alert. The garment may be a vest, hardhat, jumpsuit, belt,
band, and the
like.
[00253] In embodiments, simulation software may be built on data models
developed after a
period of data collection on personal monitoring. The simulation software may
have input
variables, such as behavioral, mechanical, environmental, and physical, and
risks may be
identified. In one example, the input variable may be a piece of personal
protective
equipment and a simulated work environment and risk factors may be identified.
[00254] In embodiments, software application resident on a device, such as an
instrument
108, 110, safety device, mobile device, or the like, may overlay safety
concerns on a real time
view of the surrounding environment using augmented reality.
Safety concerns can be pre-identified or can also be identified in real time.
[00255] In an embodiment, certain behaviors may be rewards and incentives
offered to
workers who do the right thing safety/compliance-wise based on analysis of
collected data.
For example, if the data collection indicates that the worker fell and then
checked in to the
nurses' office within a set period of time, they may be rewarded with a meal
voucher or the
like. Rewards may be given for other compliant behavior, such as checking an
instrument
back in to a tool crib, tagging instrument data with a location-based NFC tag,
wearing PPE
correctly, checking in with another worker, and the like.
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[00256] Commercially available wearable devices useful in the disclosed
systems and
methods include devices such as the Zephyr BioHarnessTM, Aframe Digital
MobileCare
Monitor, BodyMedia FIT, Nonin, Valence11 Performtek, Gaitometer, Wahoo Strap
Monitor,
Stress Thermometer, and others.
[00257] Continuing with another example of an application of the worker safety
system, an
application, which may be executing on instruments 108/110, devices 118, the
server 130 or
on a third party device, may prepare a dynamic map view of node location in
the ad-hoc P2P
or mesh network to monitor and display one or more node locations. The map may
display
relative location without reference to an area map, absolute location with
reference to an area
map, or 3D location on a topographic map or tunnel system. The map view may
present
alarm locations. In embodiments, a plurality of instruments 108/110, which may
be enabled
to communicate in the wireless network 104 or may be NFC-enabled, may transmit
data (e.g.,
sensed data, assignment data, location data, calibration status, etc.) to the
server 130, at least
partially transmitted by the wireless network 104, wherein the data may be
further displayed
in the map view.
[00258] Continuing with another example of an application of the worker safety
system,
real-time information signage may be used in conjunction with data collected
from
instruments 108, 110. For example, a real-time sign may be in electronic
communication
with one or more instruments 108/110, devices 118, the server 130 or a third
party device
such as by WiFi, Bluetooth, RFID or the like. The real-time sign may be
located in an area
and may display data based on an alarm from a nearby instrument 108, 110 and
may serve as
a remote alarm. The data may be transmitted directly to the sign using the
wireless network
104 or may be transmitted to the cloud where it is processed to determine if
it should be
displayed on the real-time information sign. In embodiments, a plurality of
instruments
108/110, which may be enabled to communicate in the wireless network 104 or
may be NFC-
enabled, may transmit data (e.g., sensed data, assignment data, location data,
calibration
status, etc.) to the server 130, at least partially by the wireless network
104, wherein the data
may be displayed by the real-time sign.
[00259] In another example of an application of the worker safety system, data
collected
from instruments 108, 110, such as noise dosimeters, may be used to alarm
workers. For
example, if a gas detector tripped a detection threshold but a noise dosimeter
indicated noise
above a certain decibel range, the gas detector instrument will be signaled to
relay its alarm
via haptic and illuminated messaging as well as an audible alarm. Further, the
alarm message
may also be displayed on a nearby real-time informational sign.
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[00260] In another example of an application of the worker safety system, data
collected
from instruments 108, 110 may determine an amount of oxygen in the
environment. Under
certain oxygen concentration conditions, a catalytic bead sensor may not work
so the
instrument may provide a warning. A remotely located supervisor may be alerted
to the
situation and deploy additional resources, such as personnel or different
sensors, to the area to
ensure safe and accurate monitoring.
[00261] In another example of an application of the worker safety system, data
collected
from instruments 108, 110 may be used in combination to trigger various levels
of
alert/alarm. For example, if an instrument reads a high carbon monoxide level,
an alarm may
be sounded but it may only be sounded at the instrument that made the reading.
If an
instrument's accelerometer determines that a man is down, an alarm may be
sounded on the
instrument as well as a few nearby instruments as determined by presence in
the same
wireless network 104 or proximity (e.g. GPS location, same NFC check-in to a
location,
manually identified location). If an instrument determines that both carbon
monoxide is high
and a man down is down, a critical alarm may be sounded on the instrument, to
nearby
workers, and in a wide area.
[00262] In yet another example of an application of the worker safety system,
the system
may be used for leak detection / pipeline monitoring. For example, sensors for
pipeline leak
inspections for safety and compliance monitoring, such as vehicle- or drone-
mounted gas
detectors, thermal conductivity or IR sensors, optical sensors, underground
sensors, gas
utility instruments and the like used to detect leaks may transmit data to the
cloud or other
remote location directly or through a device 118 or gateway 131, 112. In this
example, the
drone may be operated remotely in a two-way fashion so that control can be
done locally or,
for example, if the area needs to be evacuated, control can be remote.
Applications may use
the data to remotely configure the sensors and maintain the status of the
sensors.
[00263] In still another example of an application of the worker safety
system, the system
may obtain data from eye wash stations, chemical showers, first aid stations,
AED/defibrillator, fire extinguishers, sorbent stations or other fixed assets
124. In one
example of an eye wash station or chemical shower, sensors may be placed at
the
station/drain to detect hazards/toxins that are being washed off a user,
wherein the sensors
may communicate data back to the cloud or remote location by any communication
method
described herein, either directly or through a device 118 or gateway 131, 112.
In
embodiments, the sensors may be stand-alone sensors with remote communications
capability or may have local communications capability at a nearby dock or
instrument that
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further transmits the data. In any event, such infolination may be used in an
application used
by first responders to determine what equipment/personnel to deploy. The data
may be
combined with other data being collected by the worker safety system that may
be localized
to the same area through the use of a shared assignment (e.g. NFC tags) or a
known location
(e.g. GPS or known fixed asset 124 fixed location). Continuing with this
example, the drain
sensor may determine particular toxins and a sensor in a smoke detector may
indicate an
identity of particulates in the air from a fire, in addition to temperature
and visibility data.
Images may also be captured from a nearby camera. These data combined together
may alert
a first responder that not only is there a fire, but it is a chemical fire and
what the specific
chemical it is that has caused the fire. Second responders may also be alerted
as to what the
specific cleanup needs will be. Thus, without any on-site personnel calling an
emergency
number and explaining the situation, first and second responders may have
unprecedented
situational awareness.
[00264] Continuing with this example, secondary alarms may be generated from
an
eyewash/shower pull. An inventory of items in the area may be needed in order
to generate
the secondary alarms, wherein the inventory is known at the remote location so
that it gets
displayed to first and second responders upon the eyewash/shower pull or the
inventory is
gathered by a nearby instrument and transmitted remotely. The inventory may
include
information such as strong acid present, tank of phosphine present, gases
present, chemicals
present, combination of gases and chemicals present, or any information that
would be on a
posted hazard placard.
[00265] Continuing with the example of fixed assets 124 contributing to the
worker safety
system, a nearby sensor or integrated sensor may be able to transmit data
regarding the kind
of fire extinguisher that was used during a fire, such as a water, foam, dry
powder, carbon
dioxide, ABC, wet chemical, metal, and the like, or what kind of sorbent was
utilized for a
spill. Such information may be useful to a first or second responder in
determining
equipment and personnel to deploy.
[00266] Continuing with the example of fixed assets 124 contributing to the
worker safety
system, a sensor in area that sense an acid spill or other like hazard may
transmit data back to
a remote location for processing. Depending on the kind of hazard detected,
instructions or
information may be transmitted to devices in the area, displayed on a real-
time information
signage, transmitted to responders, and the like. For example, directions to
the nearest
eyewash/shower may be transmitted to instruments or real-time signage in the
area upon
sensing an acid spill or other hazard. If there are multiple hazards, the
instructions may be
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specific as to which station to go to if one or more have not been maintained
or are already in
use, which would be known from sensed data at that location. Nearby
instruments may also
be informed of the hazard, of the activation of a nearby eyewash/shower
station, or asked to
check in with the user of a nearby instrument or warned to stay away from an
area. When a
first worker is asked to check in with a second worker, they may receive
reminders of the
request until the worker safety system detects that the workers are near each
other or if some
other proof of contact has been transmitted. For example, a voice print from
the second
worker or an image of the second worker may be recorded with the instrument or
device of
the first worker doing the checking.
[00267] Continuing with the example of fixed assets 124 contributing to the
worker safety
system, integrated sensors with an eyewash station or shower may be used to
automate and
accelerate periodic testing of flow rate, total volume, water temperature,
salinity, pH, and the
like, in respect of safety inspections, compliance with local or federal
requirements, and to
predict the need for maintenance. With the integrated sensors in communication
with the
worker safety system, automated maintenance reminders may be delivered,
automated
records may be created of testing results and technicians performing tests,
automated
certificates of compliance may be generated, performance statistics may be
gathered, and the
like.
[00268] In embodiments, one component of the worker safety system is to
perfonit a job
hazard analysis (JHA) and then apply the hierarchy of hazard controls. The
specific job is
analyzed to understand various safety-related aspects, such as an
identification of tasks, an
identification of potential hazards (e.g. gas, electrical, chemical, thermal,
noise, etc.), and the
like. The worker safety system may have the information about various tasks
and known
potential hazards and pay perform an analysis to determine if the hazard can
be eliminated
from the task. If not, the worker safety system may recommend a way to
mitigate the
hazard. For example, certain controls may be used to minimize hazards, such as
engineering/mechanical controls. Altered behavior such as through training,
real-time
signage as discussed herein, instructional messages, and the like may be used
to minimize
hazards. Administration (e.g. scheduling) may also be useful in minimizing
hazards.
[00269] In embodiments, the worker safety system may determine, based on the
identified
hazard and task, an appropriate PPE or other protective technology (e.g. foam
protection,
hearing protection, fall, etc.) to use to minimize a hazard. The worker safety
system, through
use of connected instruments and devices may determine if the correct subtype
of PPE was
ultimately selected by the worker, if the selected PPE has been maintained, if
the selected
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PPE has been donned or is otherwise in use, if the selected PPE is being used
properly, and
the like. For example, a job may require use of an air purifying respirator
that filters in a
chemical or mechanical way to block dust, fumes or gases. The worker safety
system may
recommend a disposable versus a re-usable/refillable respirator based on the
task, the worker
safety system may determine if the re-usable respirator has been properly
maintained, and
based on a pressure reading from the respirator, the worker safety system may
determine that
the respirator is in proper use. Further, the air purifying respirator may be
equipped with a
sensor, such as an RFID. If the worker safety system detects that a worker is
in an area
requiring the PPE or has indicated that a task has begun requiring the PPE but
the RFID is not
detected by the worker's instrument, an alarm may sound.
[00270] In another example, the worker safety system may determine, based on
the
identified hazard and task, that a self-contained breathing apparatus is
required (SCBA).
Sensors on the supplied air tank may be used to determine quality, efficacy
(e.g. filter-
mounted sensor), pressure (e.g. hose- or mouthpiece-mounted sensor),
operational status, and
the like. The sensors may communicate with beacons, devices, instruments,
gateways or
directly to the cloud or other remote location. Based on the sensor readings,
the worker
safety system can anticipate or predict maintenance based on usage and
operational status
instead of on a schedule. The worker safety system can store pressure test
results for annual
certification. The worker safety system can help set up a replacement tank, if
necessary.
[00271] In an embodiment, the worker safety system may determine, based on the
identified
hazard and task, that fall protection is required, such as a harness, a self-
retracting lifeline,
rails/guards, retrieval equipment, and the like. A sensor attached to a worker
or integrated in
an instrument that is with the user may be used to determine if the worker is
in the air.
Further, knowing that data, the worker safety system can determine if the
appropriate fall
protection equipment has been checked out by the worker, if that fall
protection has been
maintained if they do have it on, if the protective equipment is being worn,
and if they are
using it correctly.
[00272] Various gas monitors that may be used in the worker safety system may
include gas
sensors (e.g. IR, (LED), LEL, catalytic bead, electrochemical, redundant gas
sensors),
humidity sensor, temperature sensor (e.g. to determine heat stress), a wind
sensor, a
microphone, an accelerometer (e.g. to measure lack of motion in order to
further determine
man-down, acceleration/deceleration to determine a fall), particulate sensor,
a barometer,
biometric sensors, phase, time of flight, signal strength, GPS or other
location-sensing
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technology, a panic button (e.g. to sound a loud alarm, to transmit a signal
remotely), NFC,
Bluetooth, radio module, WiFi, integrated cellular technology, and the like.
[00273] In one mode, alarms may be triggered based on set thresholds, such as
detection of
one or more particular gases or detection of a threshold amount of gas. In
another mode, the
gas detection instrument may include a dedicated panic button. For example, an
alarm may
be sounded when the panic button is pressed and held for 3 seconds. This may
allow the user
to alert others at the press of a button in the event of distress. In another
mode, the gas
detection instrument may be programmed with a man down alarm. For example, if
the
instrument does not detect motion via a built-in accelerometer for a
predetermined number of
seconds, an alarm may be triggered and teammates may be alerted. In yet
another mode,
alarms may provide an early warning below a low alarm set point. For example,
when a gas
concentration exceeds an Acknowledgeable Gas Alert set point, the instrument
may activate
the alarm indicators to alert the user that she may be approaching a dangerous
condition. The
user may need to take preliminary or mitigating action, but can acknowledge
and silence the
alert while she continues her work. If the condition persists beyond 30
minutes, the alert may
be reactivated.
[00274] The portable environmental sensing device or gas detection instrument
may include
a rugged case design, featuring field replaceable external dust filters to
prevent clogs, plastic
edges to prevent ovennold peeling, plastic rails to reduce overmold tearing, a
plastic ridge to
protect external sensor filters when facedown, and a recessed display to
protect from
scratches.
[00275] Gas monitors useful in the worker safety system may be portable, free-
standing,
fixed, battery-powered, wall-mounted with fixed line power, modular, and the
like. In
embodiments, each form factor may enable different functions or capabilities
of the gas
monitor. In embodiments, a modular gas monitor may take the form of a central
sensing unit
that can engage with various form factors. For example, the modular gas
monitor may be
able to engage with a free-standing base, a slot in a wall to engage with line
power, a robotic
unit, a piece of heavy equipment such as a bulldozer, crane, etc., and the
like.
[00276] In engaging with a free-standing base, the central sensing unit may be
disposed in
the base in a downward facing manner which protects it from the environment
and allows
substantially 360 degree access to environment. The free standing base may
have a speaker
to sound alarms in an area. The speaker may be a piezo-based speaker that may
be
electronically designed for intrinsic safety. The central sensing unit may be
designed with
bumps or other engagement features on the surface of the modules to prevent
them from
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sliding out of the base. The receiving portion of the base may be designed to
interact with the
engagement features.
[00277] In embodiments, the central sensing unit may emit a loud sound during
calibration
and during setup (e.g. 108 dB). There may not be an electronic way to control
the sound by
operation or by regulation. An accessory component may be provided for
placement over the
audio output to dampen the sound. The geometric shapes inside the accessory
component
may provide additional surface area to absorb the sound.
[00278] In embodiments, monitors useful in the worker safety system may be
area monitors,
such as perimeter monitor (e.g. at the edge of refinery), dust/particulates
monitoring,
noise/sound level, gases/fugitive emissions, chemicals/toxins, fence line
monitoring (e.g.
cordon off an area), and the like. In an embodiment, mere placement of the
area monitors
and establishment of a peer network, as described herein, may cause the auto-
establishment
of fence lines and perimeters.
[00279] While area monitors 110 themselves may sense an environmental
parameter that
may trigger an alarm, sending of a communication, controlling another device
or system, and
the like, area monitors 110 may receive a report from a device 108, such as
through the
wireless network 104, and sound an alarm that may be audible widely. Area
monitors 110
may receive a report from a device 108 or other network node, such as through
the wireless
network 104, and send out a communication to other devices 108 and monitors
110. Area
monitors 110 may receive a report from a device 108, such as through the
wireless network
104, and control another device or system in response to the report.
[00280] Turning now to describing particular instruments that may be used in
the worker
safety system, one such instrument is a portable electrochemical gas sensing
apparatus 108,
or badge reader.
[00281] Toxic and combustible gas sensing instruments are important devices
for many
industrial and other applications, such as for safety, environmental and
emissions monitoring,
quality and process control, clinical diagnostic applications, and the like.
In general, such
instruments are portable and include sensors that are sensitive and accurate.
[00282] An instrument with an electrochemical sensor may be used to measure
the
concentration of a specific gas. The basic components of an electrochemical
sensor include a
working (sensing) electrode, a counter electrode, and optionally a reference
electrode. These
electrodes are typically enclosed in a housing and are in contact with a
liquid or solid
electrolyte. The working electrode is typically on the inner face of a
membrane, such as
Teflon, which is porous to gas, but impermeable to the electrolyte.
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[00283] The gas to be detected diffuses into the sensor and through the
membrane to the
working electrode and electrolyte. The electrolyte may be an aqueous solution
of an acid, an
alkali, an ionic liquid, or a mineral salt; examples are sulfuric acid,
phosphoric acid,
potassium hydroxide, lithium chloride, and lithium perchlorate. The
electrolyte may also be
of an organic type such as tetraethyl ammonium perchlorate (TEAP) in a low
vapor pressure
organic solvent. When the gas reaches the working electrode and electrolyte,
an
electrochemical reaction occurs; either an oxidation or reduction depending on
the type of
gas. For example, carbon monoxide may be oxidized to carbon dioxide, or oxygen
may be
reduced to water. An oxidation reaction results in the flow of electrons from
the working
electrode to the counter electrode through an electronic circuit, such as a
potentiostat circuit,
and conversely a reduction reaction results in flow of electrons from the
counter electrode to
the working electrode through the electronic circuit. This flow of electrons
constitutes an
electric current, which is proportional to the gas concentration. The
potentiostat circuit may
be a part of an electronic processing unit in the instrument, which detects
and amplifies the
current and scales the output according to the calibration. The instrument may
then display
the gas concentration in, for example, parts per million (PPM) for toxic gas
sensors or percent
volume for oxygen sensors. Because the volume of the electrolyte can change
with time and
with environmental conditions, a reservoir chamber is usually incorporated
into the sensor to
provide additional amounts of electrolyte and/or to allow for expansion of the
electrolyte in
certain environments.
[00284] An I .F.1, (lower explosive limit) sensing instrument detects that one
or more
combustible gases are in the atmosphere. For flammable substances, there is a
limit
concentration of gas necessary for ignition. Below this limit, a mixture of
the substance in air
cannot be ignited. This limit is called the LEL. One type of LEL sensor is a
catalytic bead
sensor, which is designed to protect against the combustion of gases in the
atmosphere, rather
than specifically detect a single combustible gas. The LEL of a substance is
established by
standardized methods, and typically lies between .5 and 15% by volume. A
catalytic bead
sensor may include two measuring beads (called pellistors), each made of
porous ceramic
material embedding a small platinum wire coil. The active (sensing) bead
contains catalytic
material, while the other one is a reference bead and does not contain
catalytic material. The
beads may be matched and built into a balanced, resistive circuit, such as a
Wheatstone
bridge. When a combustible gas comes in contact with the sensor, the active
bead begins to
burn the gas causing it to increase in temperature, with a resulting increase
in the bead's
resistance that is proportional to the gas concentration. The reference bead
does not react to
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the combustible gas so its temperature and resistance does not increase. The
imbalance in the
circuit is then converted into a gas reading. Once calibrated with a
particular gas, an LEL
sensor will display values assuming all gases in the environment are that one
particular gas. If
a sensor calibrated to methane detects another gas, the instrument will
display LEL values
assuming it is truly methane. Correlation factors are therefore used to
translate a reading from
the units of the calibration gas to the units of a second gas.
[00285] A catalytic bead sensor instrument may also include a processing unit.
The
processing unit and sensor are typically enclosed within a rigid casing or
housing.
[00286] Figs. 17-19 illustrate an exemplary gas sensing apparatus 1700 with a
housing 1702
and an electrochemical sensor embedded in the housing 1702, and which is
configured to
detect one or more gases such as oxygen, carbon monoxide, methane, and
hydrogen sulfide,
along with others. In particular, housing 1702 may comprise one or more
portions 1702A,
1702B that may be formed by molded plastic or the like. When the apparatus
1700 is
assembled, the housing may be sealed. As shown, a depression 1706 is formed on
an exterior
surface of the housing 1702A, with a centrally disposed raised platform 1710
(shown in Figs.
18 and 19) in the depression 1706 formed on the exterior surface of the
housing. Depression
1706 is integral with portion 1702B and, in embodiments, results from the
molding process
giving rise to portion 1702B. The depression comprises perimeter sidewalls
defining the
boundary of the depression. In embodiments where the depression 1706 is
circular, the
depression comprises a circumferential perimeter side wall 1706A, 1706B (Fig
18). The
perimeter sidewall has two portions 1706A, 1706B in Fig. 18, as Fig. 18 is
depicting an
embodiment with a stepped-out upper portion.
[00287] The raised platform 1710 may support an electrode stack 1712 of the
electrochemical sensor within the depression 1706. The depression 1706 also
forms a second
reservoir 1708 (bounded by the outer diameter or perimeter of the raised
platform and the
bottom portion of the perimeter side wall 1706B in the embodiment shown in
Fig. 18) for
electrolyte of the electrochemical sensor. As best seen in Fig. 17, the
depression 1706 may be
cylindrical in shape to support a generally cylindrical sensor, although other
shapes may also
be used to accommodate sensors of various shapes. The sensor may include the
electrode
stack 1712 as well as the electrolyte solution in the second reservoir 1708.
[00288] As seen in Figs. 18 and 19, the depression 1706 may include a first
reservoir 1718
and a second reservoir 1708, which may aid in support of the electrode stack
1712. The
second reservoir is adapted to hold an electrolyte solution that is in fluid
communication with
the electrode stack 1712. A sensor top cap 1714 is sized to fit over the
depression 1706,
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where the cap may include a capillary hole that provides access for gas to
enter into the
electrode stack 1712.
[00289] The electrode stack 1712 may include at least one measuring electrode,
at least one
counter electrode, and optionally, at least one reference electrode, along
with a gas permeable
membrane for allowing gas to flow to the measuring electrode. The stack 1712
may include
one or more electrolyte absorption pads between the electrodes to ensure that
the electrolyte
remains in contact with the electrodes. The electrode stack 1712 may also
include various
other components, such as separators for the electrodes. For example, an
exemplary electrode
stack is shown and described in U.S. Pat. No. 8,771,490.
[00290] Housing 1702 defines an interior space 1705. Depression 1706 extends
into interior
space 1705, 2005 but is separated therefrom by the interior-space facing
surface of the
sidewall and interior-space facing surface base. A printed circuit board
assembly 1704 may
be disposed in the interior space 1705, along with a battery 1707 or other
power source for
providing power to circuitry of the apparatus 1700. For example, the assembly
1704 may
include circuitry such as a processing unit 1703 with a potentiostat circuit
in order to convert
signals from the sensor into a gas concentration reading or other parameter
related to gas
concentration exposure. Although not specifically shown, the electrode stack
1712 may be in
electrical communication with processing unit 1703, such as being connected
via wires. In
embodiments, the gas sensing apparatus 1700 does not have a user display for
display of gas
concentration readings. Instead, the gas sensing apparatus 1700 may include an
interface to
enable communication of such readings to an external device, via Bluetooth
protocol or the
like, such as to an application on a mobile phone or other computing device.
[00291] The electrode stack 1712 may be in electrical communication with an
alarm, such as
an audible alarm, a visual alarm, a vibrating alarm or the like, wherein the
alarm may be
located in the interior space of the housing, or may be wirelessly connected
to the processing
unit 1703. An alarm modality may be automatically triggered, such as through
detection of
one or more particular gases, detection of a threshold amount of gas, or the
like. An alarm or
message may be provided when determinations are made regarding various
detected
conditions, such as gas present (alert, low alarm, and high alarm), STEL
(short-term exposure
limit) reached, and TWA (time-weighted average) above a threshold. In
embodiments, an
alarm modality may feature audible, visual, and/or vibrating alarm indicators
that may be
used in multiple modes. For example, an audible indicator may be capable of
delivering a
95dB tone at a distance of 10 centimeters. In another example, the flashing
action of four
ultra-bright LEDs, two red and two blue, may attract the attention of the user
and others
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nearby. In yet another example, a vibrating alarm may provide a sensory alert
to a user in a
high noise environment.
[00292] Fig. 20 illustrates an exemplary portable combustible lower explosive
limit (LEL)
gas sensing apparatus 2000 with a housing 2002 and a combustible LEL sensor
formed
within the housing 2002. In particular, housing 2002 may comprise one or more
portions that
are assembled together. When the apparatus 2000 is assembled, the housing may
be sealed.
As shown, a sensor depression 2006 is formed on an exterior surface of the
housing 2002,
with a chamber separator 2024 integrally formed in the exterior surface to
separate an active
sensing bead 2022 in one chamber and a reference sensing bead 2020 in another
chamber of
the depression 2006. Depression 2006 is integral with housing 2002 and, in
embodiments,
results from the molding process giving rise to housing 2002. Similar to the
embodiments
shown in connection with Figs. 17-19, the depression comprises perimeter
sidewalls defining
the boundary of the depression. In embodiments where the depression is
circular, the
depression comprises a circumferential perimeter side wall.
[00293] The depression 2006 may be cylindrical in shape. A sensor flame
arrestor 2026 may
be sized to fit over the depression 2006.
[00294] An exemplary combustible gas sensor that may be integrated with
housing 2002
may include a gas sensing element including an electric heating element, a
first layer coated
on the electric heating element and comprising a precious metal catalyst
supported on a
porous oxide, the precious metal catalyst catalyzing combustion of a
combustible gas to be
detected by the sensing element, and a second layer overlaying the first
layer, and comprising
a catalytic compound capable of trapping gases which poison the precious metal
catalyst. The
sensor may also include a compensating element comprising an electric heating
element
lacking a catalyst. The sensing element and the compensating element may be
connected to a
processing unit, not shown, that may be constructed and arranged to detect
changes in
resistance of the sensing element and compensating element and to provide a
reading of the
changes. For example, an exemplary LEL sensor with gas sensing element and
compensating
element is shown and described in U.S. Pat. No. 7,007,542. Appropriate
catalytic materials
for the first and second layers may include one or more of oxide-supported
metal oxides
supported on porous oxide supports; solid acids, preferably solid superacids;
solid bases,
preferable solid superbases; and metal-loaded zeolites and clays.
[00295] Housing 2002 defines an interior space 2005. Similar to the
embodiments shown in
Figs. 17-19, depression 2006 extends into interior space 2005 but is separated
therefrom by
the interior-space facing surface of the sidewall and base. A printed circuit
board (PCB)
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assembly 2004 may be disposed in the interior space 2005, along with a battery
(not shown)
for providing power to circuitry of the apparatus 2000, and containing a
processing unit. For
example, circuitry may include the processing unit, such as with a Wheatstone
bridge circuit
in order to convert signals from the sensor into an LEL sensor reading or
other parameter
related to potential gas explosion. Each of the beads may be in electrical
communication with
the processing unit, such as being connected via wires. In embodiments, the
gas sensing
apparatus 2000 does not have a user display for display of gas concentration
readings.
Instead, the gas sensing apparatus 2000 may include an interface to enable
communication of
such readings to an external device, via Bluetooth protocol or the like, such
as to an
application on a mobile phone or other computing device.
[00296] The sensor may be in electrical communication with an alarm, such as
an audible
alarm, a visual alarm, a vibrating alarm or the like, wherein the alarm may be
located in the
interior space of the housing, or may be wirelessly connected to the
processing unit. An alarm
modality may be automatically triggered according to detection of various
conditions. In
embodiments, an alarm modality may feature audible, visual, and/or vibrating
alarm
indicators that may be used in multiple modes. For example, an audible
indicator may be
capable of delivering a 95dB tone at a distance of 10 centimeters. In another
example, the
flashing action of four ultra-bright LEDs, two red and two blue, may attract
the attention of
the user and others nearby. In yet another example, a vibrating alarm may
provide a sensory
alert to a user in a high noise environment.
[00297] The gas sensing apparatus 1700 or 2000 with housing 1702 forming part
of the
sensor and its construction provides several advantages, in that the overall
packaging size is
reduced, the component count is reduced, and potential failure modes are
reduced, as
compared to prior gas sensing instruments. In embodiments, the apparatus 1700
or 2000 may
not need a user display, in that communication such as Bluetooth may provide
display
capability to an external device. A battery for the apparatus may have a year
or more of
battery life. The manufacturing costs for the device may be reduced such that
the apparatus
may be customer disposable.
[00298] Other gas monitors may include gas sensors (e.g. IR, (LED), LEL,
catalytic bead,
electrochemical, redundant gas sensors), humidity sensor, temperature sensor
(e.g. to
determine heat stress), a wind sensor, a microphone, an accelerometer (e.g. to
measure lack
of motion in order to further determine man-down, acceleration/deceleration to
determine a
fall), particulate sensor, a barometer, biometric sensors, phase, time of
flight, signal strength,
GPS or other location-sensing technology, a panic button (e.g. to sound a loud
alarm, to
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transmit a signal remotely), NFC, Bluetooth, radio module, WiFi, integrated
cellular
technology, and the like.
[00299] Gas monitors useful in the worker safety system may be portable, free-
standing,
fixed, battery-powered, wall-mounted with fixed line power, modular, and the
like. In
embodiments, each form factor may enable different functions or capabilities
of the gas
monitor. In embodiments, a modular gas monitor may take the form of a central
sensing unit
that can engage with various form factors. For example, the modular gas
monitor may be
able to engage with a free-standing base, a slot in a wall to engage with line
power, a robotic
unit, a piece of heavy equipment such as a bulldozer, crane, etc., and the
like.
[00300] In engaging with a free-standing base, the central sensing unit may be
disposed in
the base in a downward facing manner which protects it from the environment
and allows
substantially 360 degree access to environment. The free standing base may
have a speaker
to sound alarms in an area. The speaker may be a piezo-based speaker that may
be
electronically designed for intrinsic safety. The central sensing unit may be
designed with
bumps or other engagement features on the surface of the modules to prevent
them from
sliding out of the base. The receiving portion of the base may be designed to
interact with the
engagement features.
[00301] In embodiments, the central sensing unit may emit a loud sound during
calibration
and during setup (e.g. 108 db). Regulatorily and operationally, there may not
be an electronic
way to control the sound. An accessory component may be provided for placement
over the
audio output to dampen the sound. The geometric shapes inside the accessory
component
may provide additional surface area to absorb the sound.
[00302] In embodiments, monitors useful in the worker safety system may be
area monitors,
such as perimeter monitor (e.g. at the edge of refinery), dust/particulates
monitoring,
noise/sound level, gases/fugitive emissions, chemicals/toxins, fenceline
monitoring (e.g.
cordon off an area), and the like. In an embodiment, mere placement of the
area monitors
and establishment of a peer network, as described herein, may cause the auto-
establishment
of fencelines and perimeters.
[00303] In an embodiment, portable, compact systems for estimating heat
index may
include a temperature sensor, a humidity sensor, and one or more microphones.
Portable
detection equipment 108 and area detection equipment 110, such as equipment
useful in the
worker safety system, may be used in environments where heat may negatively
affect the
equipment, the equipment's user(s), or both. For detection equipment, it may
be advisable to
monitor the environment to assure proper operation of the equipment and user
safety. While
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a temperature sensor will provide some infoiniation, an estimate of the heat
index may
provide more insight into potential heat-related impact on equipment and
users.
[00304] Historically, combined data from temperature and humidity sensors have
been used
to calculate a heat index. In some systems, a vane anemometer may be used to
calculate
wind speed and the calculated wind speed may be factored into the calculation
of heat
index. However, vane anemometers may be large, making it difficult to
incorporate into
pieces of detection equipment, potentially necessitating the need for a user
to carry multiple
pieces of detection equipment.
[00305] Figure 21 depicts a heat index estimation system 2110 which may
include at least
two microphones 2102 and temperature and humidity sensors 2104 in electrical
communication with a microprocessor 2108 for calculating a heat index from the
data
provided by the microphones 2102 and temperature and humidity sensors 2104.
The
components of the heat estimation system 2110, such as the microphones 2102
and
temperature and humidity sensors 2104, may be solid-state components for
inclusion in
detection equipment 2112. In embodiments, the microprocessor 2108 is a
component of the
equipment 2112, however, it should be understood that the system 2110 may also
or instead
include its own microprocessor and/or networking capability.
[00306] The heat index estimation system 2110 may be modular with respect to
the
detection equipment 2112 for ease of incorporation, insertion and/or removal
without
disassembly of the equipment 2112. Further, the system 2110 may be modularly
interchangeable with other modules of the equipment. The heat index estimation
system
2110 may be integrally incorporated into the detection equipment 2112. In
embodiments, the
ability to utilize solid-state temperature and humidity sensors with solid
state microphones for
estimating wind speed renders the combination, embodied in the system 2110,
capable of
fitting inside the detection equipment 2112 and capable of modularity with
respect to the
detection equipment 2112.
[00307] In embodiments, the components of the heat estimation system 2110 may
be
thermally isolated from one another.
[00308] The detection equipment 2112 may include at least one of a portable or
area
environmental sensing device, a portable or area gas sensor, a portable or
area multi-gas
detection instrument, a respirator, a lighting device, a fall arrest device, a
thermal detector, a
flame detector, and a chemical, biological, radiological, nuclear, and
explosives (CBRNE)
detector.
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[00309] The heat index estimation system 2110 may be located on a surface of
the piece of
detection equipment 2112 (Fig. 22A) or located in a cavity of the piece of
equipment that is
open to airflow 2114 (Fig. 22B).
[00310] The two microphones 2102 may be located linearly in a direction of the
airflow
2114. In embodiments, there may be at least one additional microphone 2102
located non-
linearly with respect to a line formed by the placement of the other
microphones 2102 (Fig.
23). The microphone(s) may be directly subjected to wind or may be at the
bottom of a recess
that is subjected to wind.
[00311] The microprocessor 2108 may be electrically coupled to the microphones
2102 and
sensors 2104. The microprocessor 2108 may analyze signals from the microphones
2102 for
temporal, amplitude, and frequency differences to make a wind speed
approximation, such as
a maximum wind speed, an instantaneous wind speed, an average wind speed, and
the like.
For example, the microprocessor 2108 may analyze differences between sounds
that arrive at
each microphone to calculate the speed of wind across one or both of the
microphones. In
embodiments, one microphone may be shielded. Algorithms may be used to analyze
the
noise from a microphone exposed to the wind and compare it to the noise from a
shielded
microphone and to estimate wind speed. In embodiments, the algorithm may
subtract the
signal of the non-shielded microphone to obtain a wind component without
ambient noise. In
embodiments, a time delay between one microphone and a second microphone is
used to
determine a directional component of sound as a proxy for wind direction. In
certain
embodiments, a single microphone may be used and the wind velocity may be
estimated from
the volume of the wind.
[00312] A heat index may be calculated using a polynomial equation with sensed
temperature and sensed absolute or relative humidity. The coefficients in the
common
equations known to one skilled in the art are typically based on a variety of
assumptions,
including a wind speed of approximately 5 mph. Knowing if the wind speed was
more or
less than 5 mph would enable the device to alert the user appropriately.
[00313] In some embodiments, a version of the system 2110 may not have
microphones, and
so would not use wind speed but could still provide heat index based on
temperature and
humidity data. This version of the system 2110 may also be modular with
respect to the
equipment 2112 and sized to be able to fit inside the equipment 2112. In
embodiments, data
from the humidity sensor, which may include relative and absolute humidity,
may be used for
sensor compensation.
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[00314] In embodiments, the heat index information may be provided to a user
of the
detection equipment 2112, optionally along with guidelines for self-protection
based on the
calculated heat index. For example, if a calculated heat index reaches a
threshold, the
equipment 2112 may trigger an alarm on the equipment 2112 and any other nearby
devices or
networked devices or systems. The alarm may be audible, visual, haptic or any
combination
thereof. Self-protection guidelines may be displayed on the equipment or
transmitted through
a speaker of the equipment or other devices or system. Optionally, the
calculated heat index
may trigger a communication to the user and/or other interested party, such as
a
communication, call, message, and/or email. The communication may include a
warning
and/or self-protection guidelines.
[00315] Turning now to describing particular improvements to environmental
sensing
devices 108,110, such as those that may be useful in the worker safety system,
one such
improvement relates to the use of a baseline auto-matching circuit for an LEL
sensor.
[00316] Combustible gas detectors have been widely used in industry to
detect and
monitor the presence of combustible gases or vapors for safety and
environmental purposes.
They can provide an early warning of potentially explosive conditions to
protect life and
property before onset of a hazardous situation.
[00317] Multiple gas sensing technologies may be used in such gas detectors
such as
thermal conductivity sensors, infrared (IR) sensors, semiconductor (MOS)
sensors and
catalytic bead (or pellistor) sensors. Among these, catalytic bead sensors are
most commonly
used due to their low cost, high performance and wide coverage of target
gases. A catalytic
bead sensor typically contains two ceramic beads coated onto metal, such as
platinum, wire
coils, a sensing bead and a compensating bead. The sensing bead may be
impregnated with a
noble metal catalyst, which promotes combustion of the combustible gases or
vapors, while
the compensating bead may not contain a catalyst, but compensates for
environmental effects
such as humidity and ambient temperature changes.
[00318] There are multiple ways to configure the circuit of the two beads.
Many
commercial combustible gas detectors are based on a Wheatstone bridge 2400, an
example of
which is shown in Fig. 24 and described in U.S. Patent No. 4,313,907. When an
input voltage
2401 is applied across the bridge, resistive heating of the platinum wire
coils and hence the
beads 2402, 2404 takes place. In the presence of a combustible gas or vapor,
catalytic
combustion takes place on the sensing bead 2402 and generates combustion heat,
causing an
increase in the sensing bead 2402 temperature relative to the temperature of
the compensating
bead 2404 and, thus, the sensing bead 2402 wire resistance is increased
relative to that of the
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compensating bead 2404. The increased resistance of the sensing bead 2402
generates the
differential output signal 2412 between the two circuit branches, which is
proportional to the
gas concentration in a given measurement range.
[00319] When a gas detector is manufactured, the combustible gas sensor
baseline
(differential voltage output when there is no combustible gas present) is
typically tuned to be
close to zero by selecting two matched beads with close impedance. When the
detector is
deployed for field use, the baseline may drift over the lifetime due to aging
effects of the
sensing bead 2402 and compensating bead 2404. Fig. 25 shows a graphic example
of a
typical combustible catalytic bead gas sensor's span reserve 2502 (or
sensitivity) and its
baseline (mV) 2504 change over a period of time.
[00320] The term Span Reserve harkens back to the days when gas monitoring
instruments were driven by analog circuits and calibration was performed by
adjusting the
Zero and Span potentiometers. In that era, gas was applied to the instrument
and the "span
pot" was adjusted until the reading on the display matched the concentration
of the gas being
used. If you wanted to see how much life was in your sensor, you would turn
the span
potentiometer up all the way and the subsequent reading would show you how
much reserve
sensitivity was in the sensor or how much room for adjustment there was before
the sensor
could no longer be calibrated.
[00321] Fig. 25 depicts the baseline voltage slightly above zero mV at the
beginning of
the depicted time period and decreasing over the measured time to
approximately negative
18mV at the latest stage of life depicted. Prior art approaches to address
this issue include
auto-zeroing with software in gas detectors. However, this approach results in
a
corresponding loss in the span reserve 2502 (sensitivity) as shown by the
reduction of span
reserve shown in Fig. 25 from approximately 155% down to 120 % over the same
time
period. Thus, auto-zeroing obscures the issue and does not resolve it,
allowing the
Wheatstone bridge to continue becoming more unbalanced over time.
[00322] Thus, there remains a need for balanced bridge circuit configurations
for
combustible gas detectors that can maintain span reserve (sensitivity) over
time.
[00323] Fig. 26A depicts a balanced bridge circuit 2600 having two
branches, each
connected in parallel with a power source 2601. The first branch 2620 has a
sensing bead R1
2602 and a compensating bead R2 2604 connected in series. Sensing bead RI 2602
is further
connected in parallel with a variable resistor R5 2608 and compensating bead
R2 2604 is
further connected in parallel with a variable resistor R6 2612. The second
branch 2622 has a
standard resistor R3 2610 and a standard resistor R4 2614 connected in series.
A differential
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output meter 2618 measures the baseline voltage and is disposed between the
first branch
2620 and the second branch 2622 with one side connected between the sensing
bead 2602
and the compensating bead 2604 and the other side connected between the
standard resistors
2610, 2614. This configuration may enable any unbalance of the circuit due to
changes, such
as aging or other deterioration, of the sensing bead R1 2602 or compensating
bead R2 2604
to be adjusted by varying one of the variable resistors R5 2608 or R6 2612
where the variable
resistor adjusted may be selected based on the degree of drift in bead R1 2602
relative to drift
in bead R2 2604 so as to maintain the baseline as indicated by differential
output meter 2618
reading close to zero mV. In this and the following circuits, it is understood
that the location
in the circuit of the sensing bead R1 2602 and the compensating bead R2 2604
may be
switched.
[00324] In other embodiments, a single variable resistor may be used as
shown in Figs.
26 B- 26 C. Referring to Fig. 26 B, a balanced bridge circuit 2630 is depicted
having two
branches connected in parallel with a power source 2601. The first branch 2626
has a
sensing bead R1 2602 in series with a compensating bead R2 2604. Sensing bead
R1 2602 is
further connected in parallel with a variable resistor R5 2608. The second
branch 2627 has a
standard resistor R3 2610 connected in series with resistor R4 2614. A
differential output
meter 2618 measures the baseline voltage and is disposed between the first
branch 2626 and
the second branch 2627 with one side connected between the sensing bead 2602
and the
compensating bead 2604 and the other side connected between standard resistors
R3 2610
and R4 2614. The value of variable resistor R5 2608 may be adjusted to
compensate for
changes in the resistance of sensing bead RI 2602. This solution works if the
value of
sensing bead R1 2602 is higher than that of compensating bead R2 2604.
Otherwise, the
circuit may not be able to adjust the balance point given that the parallel
connection will only
reduce the total resistance.
[00325] Referring to Fig. 26 C, a balanced bridge circuit 2640 is depicted
having two
branches connected in parallel with a power source 2601. The first branch 2628
has a sensing
bead RI 2602 and a compensating bead R2 2604 connected in series. Compensating
bead R2
2604 is further connected in parallel with a variable resistor R6 2612. The
second branch
2629 has two standard resistors R3 2610 and R4 2614 connected in series.
Although two
resistors are shown more than two may be used. A differential output meter
2618 measures
the baseline voltage and is disposed between the first branch 2628 and the
second branch
2629 with one side connected between the sensing bead 2602 and the
compensating bead
2604 and the other side connected between the standard resistors 2610, 2614.
The value of
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variable resistor R6 2612 may be adjusted to compensate for changes in the
resistance of
compensating bead R2 2604. The use of a single variable resistor may save cost
on hardware
relative to the two variable resistor embodiment of Fig. 26 A. This solution
works if the
value of sensing bead R1 2602 is lower than that of compensating bead R2 2604.
[00326] Another embodiment of a balanced bridge circuit 2700 is depicted in
Fig
230A. There are two branches connected in parallel with each other and a power
source 2601.
The first branch 2702 has a sensor bead 2602 and a compensating bead 2604
connected in
series. The second branch 2704 has two resistors, R3 2610 and R4 2616
connected in series.
As the resistances of the beads 2602, 2604 in the first branch 2702 change
with age, the ratio
of the resistors in the second branch 2704 may be adjusted to achieve the
desired baseline. To
achieve this, either R3 2610 or R4 2616 (as shown in Fig. 27A) may be a
variable resistor. A
differential output meter 2618 disposed between the two branches measures a
baseline
voltage with one side of the meter 2618 connected to the first branch 2702
between the sensor
bead 2602 and the compensating bead 2604 and the other side of the meter being
connected
to the second branch 2704 between the two resistors 2610, 2616. Whenever there
is a need to
balance the bridge circuit, the variable resistor (R3 2610 or R4 2616) will be
adjusted or
"tuned" to compensate for the relative changes of the beads R1 2602 and R2
2604 branch.
For example, if R3 2610 equals 10K ohms and the power applied to the bridge is
3V, the
simulated baseline resulting from tuning R4 2616 is shown in Fig 27B.
Referring to Fig.
27B, the baseline voltage 2708 is shown as a function of the value of variable
resistor R4
2616. This configuration facilitates adjusting the baseline voltage 2708 over
a wide range by
adjusting the value of the variable resistor R4 2616, enabling tuning the
circuit to adjust for
changes to the baseline by adjusting the value of variable resistor R4.
However, this tuning
circuit results in large changes in baseline voltage 2708 for relatively small
changes in the
value of variable resistor R4 2616.
[00327] Fig. 28A illustrates another embodiment of a balanced bridge
circuit 2800.
There are two branches connected in parallel with each other and a power
source 2601. The
first branch 2804 has a sensor bead 2602 and a compensating bead 2604
connected in series.
The second branch 2808 has two standard resistors, R3 2610 and R4 2614. The
second
branch 2808 also includes a variable resistor R5 2802, which may be connected
in parallel
with either resistor R3 2610 or R4 2614 (shown). A differential output meter
2618 disposed
between the two branches measures a baseline voltage with one side of the
meter 2618
connected to the first branch 2804 between the sensor bead 2602 and the
compensating bead
2604 and the other side of the meter being connected to the second branch 2808
between the
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two resistors 2610, 2614. Fig. 28B shows a simulation of the baseline voltage
2852 as a
function of the value of variable resistor R5 2802 when it is in parallel with
resistor R4 2614.
This circuit may enable fine-tuning of the baseline voltage over a portion of
the range of the
variable resistor R5 2802. The range over which the circuit may be finely
tuned varies
depending on whether the variable resistor R5 2802 is in parallel with R3 2610
or R4 2614.
[00328] Instead of tuning on one side, Fig. 29A shows an embodiment of a
balanced
bridge circuit 2900 that may enable tuning on both sides. There are two
branches connected
in parallel with each other and a power source 2601. The first branch 2906 has
a sensor bead
2602 and a compensating bead 2604 connected in series. The second branch 2908
comprises
two terminals of a three-terminal variable resistor (potentiometer) R3 2904
forming the
second branch. A differential output meter 2618 disposed between the two
branches
measures a baseline voltage with one side of the meter 2618 connected to the
first branch
2906 between the sensor bead 2602 and the compensating bead 2604 and the other
side of the
meter being connected to the wiper 2902 terminal of the three-terminal
variable resistor R3
2904 forming the second branch 2908. In this way, by adjusting the wiper 2902
up and down,
the second branch 2908 may be adjusted to match changes to the beads, R1 2602
and R2
2604. Fig. 29B depicts a simulation of the resulting change in baseline
differential output
2952 as the wiper 2902 is adjusted. This embodiment results in a linear tuning
curve where
the baseline differential output varies linearly with the adjustment of the
wiper 2902.
[00329] Fig. 30A shows another embodiment of a balanced bridge circuit 3000
which
is a variant of the embodiment of Fig. 29A. There are two branches connected
in parallel with
each other and a power source 2601. The first branch 3010 has a sensor bead
2602 and a
compensating bead 2604 connected in series. The second branch 3012 has a three-
terminal
variable resistor 3002, which may be a digital potentiometer, connected in
parallel to standard
resistors R3 2610 and R4 2614. The wiper 3004 of the three-terminal variable
resistor 3002
may be connected between the two standard resistors R3 2610 and R4 2614. A
differential
output meter 2618 disposed between the two branches measures a baseline
voltage with one
side of the meter 2618 connected to the first branch 3010 between the sensor
bead 2602 and
the compensating bead 2604 and the other side of the meter being connected
between to the
wiper 3004 of the three-terminal variable resistor R3 3002 and between the two
standard
resistors R3 2610 and R4 2614. In this way, by moving the wiper 3004 up and
down, the
bridge may be adjusted to match the changes of beads R1 2602 and R2 2604.
Considering the
typical baseline drift of a catalytic sensor may be small, this circuit may
enable accurate
tuning. Fig. 30B depicts a simulation of the resulting change in baseline
differential output
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3052 as the wiper 3004 is adjusted. In the middle range of the matching point,
the tuning step
is very fine. For example, assuming R3 2610 and R4 2614 is 10K ohms, R5 3002
is 100K
ohms, and the power supply 2601 is 3V, the adjustable baseline 3052 may be as
small as 2
mV.
[00330] Fig. 31 shows an embodiment of a bridge circuit 3100 being balanced
through
a digital potentiometer and microprocessor in a gas detector. There are two
branches
connected in parallel with each other and a power source 2601. The first
branch 3110 has a
sensor bead 2602 and a compensating bead 2604 connected in series. The second
branch
3112 has a three-terminal digital potentiometer 3106, connected in parallel to
two standard
resistors R3 2610 and R4 2614 connected in series. A differential A/D
convertor is disposed
between the two branches with the connection to the first branch 3110 located
between the
sensor bead 2602 and the compensating bead 2604. The connection to the second
branch
3112 is connected between the two standard resistors R3 2610 and R4 2614 to
the wiper 3108
of the digital potentiometer 3106. When the bridge circuit is balanced, the
differential output
voltage detected by microprocessor 3104 through AID convertor 3102 stays close
to zero if
there is no combustible gas present. When a significant baseline drift
happens, the differential
output will become non-zero (above the tolerance range i.e. 10mV) even if
there is no
combustible gas present. At this time, the instrument may send a command to
digital
potentiometer R5 3106 to change its position of wiper 3108 to match the new R1
2602/R2
2604 values until differential output voltage drops within a tolerance range
(i.e. 10mV).
[00331] Fig. 32A depicts another embodiment of a balanced bridge circuit
3200 which
is a variant of the embodiment of Fig. 30A. There are two branches connected
in parallel with
each other and a power source 2601. The first branch 3210 has a sensor bead
2602 and a
compensating bead 2604 connected in series. The second branch 3212 has a three-
terminal
variable resistor 3202, which may be a digital potentiometer, connected in
series between
standard resistors R3 2610 and R4 2614, while the wiper 3204 terminal is
connected to one
side of a differential output meter 2618. The other end of the differential
output meter 2618 is
connected to the first branch 3210 between the sensor bead 2602 and the
compensating bead
2604. In this way, by moving the wiper 3204 up and down, the bridge may be
adjusted to
match the changes of beads R1 2602 and R2 2604. Considering the typical
baseline drift of a
catalytic sensor may be small, this circuit may enable accurate and linear
tuning. Fig. 32B
depicts a simulation of the resulting change in baseline differential output
3252 as the wiper
3204 is adjusted. As depicted, the tuning steps are fine and linear over most
of the range of
tuning. For example, assuming R3 2610 and R4 2614 are 10K ohms, R5 3202 is 2K
ohms
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with 256 steps, and the power supply 2601 is 3V, the adjustable baseline 3252
may be as
small as 1.1 mV.
[00332] Fig. 33 depicts an embodiment of a balanced bridge circuit 3300
balanced
through a digital potentiometer and microprocessor in a gas detector. There
are two branches
connected in parallel with each other and a power source 2601. The first
branch 3310 has a
sensor bead 2602 and a compensating bead 2604 connected in series. The second
branch
3312 has a three-terminal digital potentiometer 3302, connected between two
standard
resistors R3 2610 and R4 2614. A differential A/D convertor is disposed
between the two
branches with the connection to the first branch 3310 located between the
sensor bead 2602
and the compensating bead 2604. The connection to the second branch 3312 is
connected to
the wiper 3304 of the digital potentiometer 3302. When the bridge circuit is
balanced, the
differential output voltage detected by microprocessor 3104 through A/D
convertor 3102
stays close to zero if there is no combustible gas present. When a significant
baseline drift
happens, the differential output will become non-zero (above the tolerance
range i.e. 10mV)
even if there is no combustible gas present. At this time, the microprocessor
3104 may
calculate how much tuning resistance may be needed to reduce the differential
output and
send a command to digital potentiometer R5 3302 to change its position of
wiper 3304 to
match the new R1 2602/R2 2604 values. This tuning may be done in one step and
bring down
the baseline close to zero.
[00333] Continuing with describing particular improvements to environmental
sensing
devices 108, 110, such as gas monitors, that may be used in the worker safety
system, one
such improvement relates to lead-free filters for catalytic bead sensors.
Catalytic bead sensors
used to detect combustible gases may exhibit reduced sensitivity to certain
combustible gases
such as methane, in the presence of catalyst poisons, such as hydrogen
sulfide. The effect of
hydrogen sulfide on the catalytic bead sensor may be ameliorated by the use of
filters to
remove the hydrogen sulfide from the gas passing over the sensor.
[00334] There remains an ongoing need for methods for the manufacture of
highly efficient
filters that do not contain lead.
[00335] The methods described herein produce metallic copper filters, wherein
some
embodiments of the methods disclosed herein produce nanometer-scale metallic
copper
particles. These may be in the range of 1-100 nanometers. Particles on the
nanometer scale
may be highly reactive with hydrogen sulfide and may have a high surface area
for reacting
with hydrogen sulfide. Filters prepared using the methods described herein
have a high
capacity preventing the transmission of hydrogen sulfide through the filter.
While porous
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glass fiber filters will be used throughout this specification as an exemplary
substrate in the
embodiments, it should be understood that other substrates may also be useful
in the
embodiments of the disclosure, such as alumina, silica, zirconia, and titanium
substrates.
Indeed, in some embodiments, the metallic copper particles may themselves be
used as the
filter without any need for a supporting substrate.
[00336] In one embodiment, referring to Fig. 34, a metallic copper particle
filter may be
made by preparing a solution of a copper compound (step 3402), such as copper
sulfate,
copper chloride and the like and applying the copper solution to a glass fiber
paper (step
3404). The glass fiber paper coated with the copper compound may then be dried
(step 3408)
at room temperature or at an elevated temperature. A second solution of sodium
borohydride
may be prepared (step 3410) and applied to the glass fiber paper coated with
the copper
compound (step 3412) resulting in the copper compound being reduced to
metallic copper.
The glass fiber paper coated with the metallic copper is then dried (step
3414) at room
temperature or at an elevated temperature for use in the sensor.
[00337] In another embodiment, and referring now to Fig. 35, a metallic copper
particle
filter may be made by preparing a solution of copper compound (step 3502) and
applying the
copper solution to a glass fiber paper (step 3504). The glass fiber paper
coated with the
copper solution may then be dried (step 3508) at room temperature or at an
elevated
temperature. Hydrogen in nitrogen may then be applied to the glass fiber paper
coated with
the copper compound (step 3510) resulting in the copper compound being reduced
to metallic
copper particles.
[00338] In another embodiment, and referring to Fig. 36, a metallic copper
particle filter
may be made by preparing a solution of a copper compound (step 3602),
preparing a solution
of sodium borohydride (step 3604), and mixing the two solutions (step 3608)
resulting in the
copper compound being reduced to metallic copper particles. The metallic
copper particles
may then be dried (step 3610) at room temperature or at an elevated
temperature.
[00339] Since the copper particles are small in size, the filter color may be
black instead of
bronze (color of copper large particles or pieces). The copper particles may
form a porous
material to effectively block hydrogen sulfide.
[00340] As shown in Fig. 37, a graph comparing the capacity of different
hydrogen sulfide
filters, in parts per million (ppm) Hours (hrs), is shown. The graph charts
the capacity of a
disclosed metallic copper filter created using the method of Fig. 34 (800 ppm
hrs) as well as a
lead acetate filter (1200 ppm hrs), a copper sulfate filter (531 ppm hrs), an
iron chloride filter
(40 ppm hrs), a zinc acetate filter (40 ppm hrs), a copper chloride filter (40
ppm hrs), and a
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nickel chloride filter (60 ppm hrs). The data in this graph can be interpreted
as demonstrating
that the metallic copper particle filter and the copper sulfate filter,
approach the capacity of
the conventional lead acetate filter.
[00341] The effectiveness of filters made using the methods described herein
may be seen in
Fig. 38, a graph depicting the change in methane sensitivity (in mV/% LEL) of
a sensor over
time in an atmosphere having 25 parts per million (ppm) of hydrogen sulfide.
In the absence
of a filter 3910, the sensitivity falls off quickly. However, the presence of
a filter of lead
acetate 3902 or metallic copper 3904 show very little fall off in sensitivity
over time spent in
the presence of hydrogen sulfide. A filter of copper sulfate 3908 provides
some protection
but there is a noticeable decrease in sensitivity relative to the metallic
copper filter 3904 and
always remains below that of metallic copper.
[00342] Continuing with describing particular improvements to environmental
sensing
devices 108, 110, such as gas monitors, that may be used in the worker safety
system, one
such improvement relates to mechanical stability. Catalytic bead combustible
gas sensors
have been widely used in industry to detect the presence of combustible gases
and vapors for
safety purposes and to provide a warning of potentially hazardous conditions
before these
gases and vapors reach explosive levels. Commercial catalytic bead sensors
detect gases
through the use of electrically heated helical filaments typically embedded
within a catalytic
material. The mechanical stability of this assembly is compromised by the
weight of the
catalytic material itself. Thus, there remains a need for combustible gas
sensors with
improved mechanical stability.
[00343] Referring to Fig. 39A & 39B, a gas sensing or compensating element of
a
combustible gas sensor is shown. A cantilever support 4002 is connected to a
coated coil
4004 and attached to a third support post 4008. The coated coil 4004 is
attached to two
support posts 4010. The coated coils is coated via chemical vapor deposition
(CVD) with an
insulating material that keeps the winds of the coil from touching and
creating hot spots and
prevents the cantilever support 4002 from shorting the coil turns
electronically. In
embodiments, the cantilever support 4002 supports the wire that the coil 4004
is a part of, and
may be connected to the coil by soldering, but it is understood that other
attachment methods
are contemplated as well. In some embodiments, the cantilever 4002 is disposed
or threaded
entirely through the coil 4004 and emerges on the other side of the coil, such
as shown in Fig.
39A, while in other embodiments, the cantilever 4002 is only partially
disposed or threaded
through the coil. In some embodiments, the cantilever 4002 supports the coil
4004 from
beneath, such as in Fig. 39B, or from above the coil. The coated coil 4004 is
part of a
92
resistance wire whose ends are attached to the support posts 4010. While in
some
embodiments, the cantilever does not touch the coil, it is possible for the
cantilever to touch
the coil since the coil is coated with an insulating material, such as in Fig.
39C.
[00344] Referring to Fig. 40, a bead 4102 is fabricated to coat both the
cantilever
support 4002 and the coil 4004_ The bead 4102 may be of a catalytic material
or may be
another material, such as ceramic, coated with or mixed with a catalytic
material, such as
platinum or palladium. In an embodiment, the bead 4102 may include an inner
layer of a
porous oxide-supported precious metal catalyst that catalyzes the combustion
reaction, and an
outer layer of a porous oxide-supported catalytic material that effectively
traps catalyst
poisons. Formation of the bead 4102 (either a sensing bead or a compensating
bead) may
occur by various processes, such as those described in United States Patent
No. 7,007,542.
[00345] In operation, electrical currents are passed through the coil 4004
causing it to
become heated. Combustible gases that come in contact with the catalytic
material of the
bead 4102 coating the coil 4004 may combust at a lower than normal ignition
temperature,
causing further heating of the coil 4004 and a change in its electrical
resistance which is
detected by sensor-associated electronics.
[00346] Adding a third support post 4008 to the gas sensing element enables
use of the
cantilever 4002 to mechanically support the excess weight of the catalytic
bead 4102 and also
allow for a reduced coil wire size to reduce the power necessary to run the
system_ The
cantilever 4002 may be threaded through the center of the coil 4004 and is
subsequently
coated together with the coil 4004 within the bead 4102 during bead
fabrication, thus
ensuring that the cantilever 4002 and the coil 4004 are mechanically joined
for more stable
support.
[00347] By using only three support posts, fabricating the bead 4102 is more
convenient
with access to the entire open side (opposite the cantilever 4002) of the coil
4004. Further,
less power loss is observed when only requiring one additional support as less
additional
operational power is required to overcome associated heat loss with three
supports over
designs that incorporate more than three supports. Mechanical stability of the
assembly is
greatly improved with the cantilever 4002 as exhibited by the results of
durability testing,
which may involve dropping an instrument containing the gas sensing element
from one
meter onto concrete. Without the cantilever 4002, the sensor withstands fewer
drops (e.g.
eight) before malfunction or breakage, but with the cantilever 4002, the
sensor can withstand
numerous drops (e.g. greater than fifty-two). The cantilever 4002 also enables
the use of very
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thin coil wire, such as 0.5 mil, to reduce the power necessary to run the
system. Decreased
wire diameter may result in higher resistance, and concomitantly, a reduction
in the sensor's
overall electrical requirements (power and current) in achieving a particular
operating
temperature. Such a reduction in power requirement may result in extending the
life of the
power supply or in enabling the further reduction of the size of the power
supply.
[00348] Additional Statements of the Disclosure
[00349] In some implementations, catalytically activated combustible gas
sensing elements
may be described in the following clauses or otherwise described herein and as
illustrated in
Figs. 39A, 39B, 39C, and 40.
[00350] CLAUSE SET A
[00351] Clause 1. A catalytically activated combustible gas sensing element,
comprising: a
filament of resistance wire forming a coil, wherein a first end of the
resistance wire is
attached to a first support post and a second end of the resistance wire is
attached to a second
support post; a cantilever support supporting the coil, wherein the cantilever
support is
attached to a third support post; and a catalytic bead substantially
surrounding the coil and
cantilever.
[00352] Clause 2. The gas sensing element of clausel wherein the resistance
wire is coated
via chemical vapor deposition with an insulating material preventing winds of
the coil from
electrically conducting through an exterior surface of the wire.
[00353] Clause 3. The gas sensing element of clause 1 wherein the cantilever
support is
attached to the resistance wire.
[00354] Clause 4. The gas sensing element of clause 3 wherein the cantilever
support is
attached to the resistance wire by soldering.
[00355] Clause 5. The gas sensing element of clause 3 wherein the cantilever
support is
attached to a single coil of the resistance wire.
[00356] Clause 6. The gas sensing element of clause 3 wherein the cantilever
support is
attached to more than one, but not all coils of the resistance wire.
[00357] Clause 7. The gas sensing element of clause 3 wherein the cantilever
support is
attached to all coils of the resistance wire.
[00358] Clause 8. The gas sensing element of clause 1 wherein the cantilever
support is
disposed within, but does not contact the resistance wire.
[00359] Clause 9. The gas sensing element of clause 1 wherein the cantilever
support is
disposed below the resistance wire.
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[00360] Clause 10. The gas sensing element of clause 1 wherein the cantilever
support is
disposed above the resistance wire.
[00361] Clause 11. The gas sensing element of clause 1 further comprising a
bead
enveloping the cantilever support and the resistance wire.
[00362] Clause 12. The gas sensing element of clause 11 wherein the bead
comprises a
catalytic material.
[00363] Clause 13. The gas sensing element of clause 12 wherein the catalytic
material
comprises one or both of platinum or palladium.
[00364] Clause 14. The gas sensing element of clause 11 wherein the bead
comprises a
ceramic material.
[00365] Clause 15. The gas sensing element of clause 11 wherein the bead
comprises an
inner layer of a porous oxide-supported precious metal catalyst and an outer
layer of a porous
oxide-supported catalytic material.
[00366] Clause 16. A catalytically activated combustible gas sensing element
comprising: a
filament of resistance wire forming a coil, wherein the resistance wire is of
a diameter equal
to or less than 0.5 millimeters, wherein a first end of the resistance wire is
attached to a first
support post and a second end of the resistance wire is attached to a second
support post; and
a cantilever support adapted to support the coil, wherein the cantilever
support is attached to a
third support post; wherein the resistance wire can withstand more than eight
drops of one
meter onto concrete without breakage.
[00367] Clause 17. The gas sensing element of clause 16 wherein the cantilever
support is
attached to the resistance wire.
[00368] Clause 18. The gas sensing element of clause 17 wherein the cantilever
support is
attached to a single coil of the resistance wire.
[00369] Clause 19. The gas sensing element of clause 17 wherein the cantilever
support is
attached to more than one, but not all coils of the resistance wire.
[00370] Clause 20. The gas sensing element of clause 17 wherein the cantilever
support is
attached to all coils of the resistance wire.
[00371] Clause 21. The gas sensing element of clause 16 wherein the cantilever
support is
disposed within, but does not contact the resistance wire.
[00372] Clause 22. The gas sensing element of clause 16 wherein the cantilever
support is
disposed below the resistance wire.
[00373] Clause 23. The gas sensing element of clause 16 wherein the cantilever
support is
disposed above the resistance wire.
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[00374] Clause 24. The gas sensing element of clause 1 further comprising a
bead
enveloping the cantilever support and the resistance wire.
[00375] Clause 25. The gas sensing element of clause 24 wherein the bead
comprises a
catalytic material.
[00376] Clause 26. The gas sensing element of clause 25 wherein the catalytic
material
comprises one or both of platinum or palladium.
[00377] Clause 27. The gas sensing element of clause 24 wherein the bead
comprises a
ceramic material.
[00378] Clause 28. The gas sensing element of clause 24 wherein the bead
comprises an
inner layer of a porous oxide-supported precious metal catalyst and an outer
layer of a porous
oxide-supported catalytic material.
[00379] In some implementations, portable electrochemical gas sensing
apparatus may be
described in the following clauses or otherwise described herein and as
illustrated in Figs. 17
- 20.
[00380] CLAUSE SET B
[00381] Clause 1. A portable electrochemical gas sensing apparatus,
comprising: a housing
comprising an exterior surface that defines an interior space, wherein at
least one depression
is formed in the exterior surface; an electrochemical gas sensor at least
partially disposed
within the at least one depression of the housing; and a processing unit
disposed in the
interior space of the housing and in electrical communication with the
electrochemical gas
sensor.
[00382] Clause 2. The apparatus of clause 1, wherein the components of the
electrochemical
gas sensor comprise an electrode stack, wherein the electrode stack comprises
at least one gas
permeable membrane, at least one electrolyte absorption pad, at least one
measuring
electrode, and at least one counter electrode.
[00383] Clause 3. The apparatus of clause 1, wherein the at least one
depression comprises
a first reservoir, a second reservoir, and a centrally-disposed raised
platform formed within
the at least one depression of the exterior surface, and the platform is
shaped to support, at
least in part, the electrode stack.
[00384] Clause 4. The apparatus of clause 3, wherein the electrode stack rests
on the raised
platform and covers the second reservoir.
[00385] Clause 5. The apparatus of clause 3, wherein the second reservoir is
adapted to hold
an electrolyte solution that is in fluid communication with the electrode
stack.
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[00386] Clause 6. The apparatus of clause 2, wherein the electrode stack is in
electrical
communication with an alarm modality, wherein the alarm modality is disposed
in the
interior space of the housing.
[00387] Clause 7. The apparatus of clause 6, wherein the alarm modality is
wirelessly
connected to the processing unit.
[00388] Clause 8. The apparatus of clause 3, further comprising a cap sized to
fit over the at
least one depression.
[00389] Clause 9. The apparatus of clause 8, wherein the cap comprises a
capillary hole
providing access for gas entry into the electrode stack.
[00390] Clause 10. The apparatus of clause 1, wherein the electrochemical
sensor senses
one or more of: oxygen, carbon monoxide, methane, and hydrogen sulfide.
[00391] Clause 11. The apparatus of clause 1, wherein the interior space of
the housing is
sealed.
[00392] Clause 12. The apparatus of clause 11, further comprising a power
source disposed
in the interior space of the housing to power the alarm modality.
[00393] Clause 13. A portable combustible lower explosive limit (LEL) gas
sensing
apparatus, comprising: a housing comprising an exterior surface and that
defines an interior
space, wherein at least one depression is formed in the exterior surface; a
combustible gas
sensor at least partially disposed within the at least one depression of the
housing; and a
processing unit disposed in the interior space of the housing and in
electrical communication
with the combustible gas sensor.
[00394] Clause 14. The apparatus of clause 13, wherein the at least one
depression holds at
least one catalytic sensing bead in a chamber.
[00395] Clause 15. The apparatus of clause 14, wherein the at least one
catalytic sensing
bead is in electrical communication with components of the apparatus disposed
in the interior
space.
[00396] Clause 16. The apparatus of clause 13, wherein the at least one
depression
comprises two chambers with a chamber separator integrally formed in the
depression,
wherein each chamber is adapted to hold at least one catalytic sensing bead.
[00397] Clause 17. The apparatus of clause 13, further comprising a sensor
flame arrestor
that covers the at least one depression.
[00398] Clause 18. The apparatus of clause 13, wherein the combustible gas
sensor
comprises: a gas sensing element including: an electric heating element, a
first layer coated
on the electric heating element and comprising a precious metal catalyst
supported on a
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porous oxide, the precious metal catalyst catalyzing combustion of a
combustible gas to be
detected by the sensing element, and a second layer overlaying the first
layer, and comprising
a catalytic compound capable of trapping gases that poison the precious metal
catalyst, said
catalytic compound being supported on a porous oxide; a compensating element
comprising
an electric heating element, said compensating element not including a
catalyst capable of
catalyzing combustion of a combustible gas to be detected by the sensing
element; and a
processing unit to which the sensing element and compensating element are
connected, the
processing unit being constructed and arranged to detect changes in resistance
of the sensing
element and compensating element, and to provide a reading of said changes.
[00399] Clause 19. The apparatus of clause 18, wherein the catalytic materials
for the first
and second layers comprise one or more of oxide-supported metal oxides
supported on
porous oxide supports, solid acids, solid bases, and metal-loaded zeolites and
clays.
[00400] Clause 20. The apparatus of clause 2, further comprising, at least one
reference
electrode.
[00401] In some implementations, circuits for tuning an unbalanced Wheatstone
bridge
circuit may be described in the following clauses or otherwise described
herein and as
illustrated in Figs. 24 - 33.
[00402] CLAUSE SET C
[00403] Clause 1. A circuit for tuning an unbalanced Wheatstone bridge
circuit in a
combustible catalytic gas sensor to minimize baseline voltage drift,
comprising: a first branch
comprising a sensor bead in series with a compensating bead wherein the
temperature and
resistance of the sensing bead increases in comparison to the compensating
bead when in the
presence of a combustible gas, a second branch, connected in parallel with the
first branch,
comprising two resistors; a meter to measure a baseline voltage differential
between the two
branches connected between the beads on the first branch and between the two
resistors on
the second branch; and one or more variable resistor in parallel with each of
or both of the
sensor bead and the compensating bead; wherein the one or more variable
resistors may be
adjusted to maintain the baseline voltage differential as indicated by the
meter at about zero
volts.
[00404] Clause 2. The circuit of clause 1 wherein the one or more variable
resistor in
parallel with each of or both of the sensor bead and the compensating bead
comprises a
variable resistor in parallel with the sensing bead and a variable resistor in
parallel with the
compensating bead.
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[00405] Clause 3. The circuit of clause 1 wherein the one or more variable
resistor in
parallel with each of or both of the sensor bead and the compensating bead
consists of a
variable resistor in parallel with sensing bead.
[00406] Clause 4. The circuit of clause 1 wherein the one or more variable
resistor in
parallel with each of or both of the sensor bead and the compensating bead
consists of a
variable resistor in parallel with the compensating bead.
[00407] Clause 5. A circuit for tuning an unbalanced Wheatstone bridge
circuit in a
combustible catalytic gas sensor to minimize baseline voltage drift,
comprising: a first branch
comprising a sensor bead in series with a compensating bead wherein the
temperature and
resistance of the sensing bead increases in comparison to the compensating
bead when in the
presence of a combustible gas, a second branch, connected in parallel with the
first branch,
comprising a first and a second resistance; a meter to measure a baseline
voltage differential
between the two branches connected between the beads on the first branch and
between the
two resistors on the second branch; and wherein the first resistance comprises
one of a
variable resistor or a fixed resistor in parallel with a variable resistor;
and wherein the second
resistance comprises one of a variable resistor or a fixed resistor in
parallel with a variable
resistor, but wherein the first resistance or second resistance comprises at
least one variable
resistor; wherein the at least one variable resistor may be adjusted to
maintain the baseline
voltage differential as indicated by the meter at about zero volts.
[00408] Clause 6. The circuit of clause 5 wherein the first resistance
comprises a fixed
resistor.
[00409] Clause 7. The circuit of clause 5 wherein the first resistance
comprises a fixed
resistor in parallel with a variable resistor.
[00410] Clause 8. The circuit of clause 5 wherein the second resistance
comprises a variable
resistor.
[00411] Clause 9. The circuit of clause 5 wherein the second resistance
comprises a fixed
resistor in parallel with a variable resistor.
[00412] Clause 10. A circuit for tuning an unbalanced Wheatstone bridge
circuit in a
combustible catalytic gas sensor to minimize baseline voltage drift,
comprising:a first branch
comprising a sensor bead in series with a compensating bead wherein the
temperature and
resistance of the sensing bead increases in comparison to the compensating
bead when in the
presence of a combustible gas, a second branch comprising a potentiometer
comprising a first
and a second leg having a first and second resistance, respectively, the first
resistance in
parallel with the sensor bead and the second resistance in parallel with the
compensating
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bead; and a meter to measure a baseline voltage differential between the two
branches
connected between the beads on the first branch and between the first and
second leg of the
potentiometer; wherein the potentiometer is adjusted to maintain the baseline
voltage
differential as indicated by the meter at about zero volts.
[00413] Clause 11. The circuit of clause 10 further comprising one or both of
a primary
resistor in parallel with the first leg of the potentiometer and a secondary
resistor in parallel
with the second leg of the potentiometer.
[00414] Clause 12. The circuit of clause 10 further comprising one or both of
a primary
resistor in series with the first leg of the potentiometer and a secondary
resistor in series with
the second leg of the potentiometer.
[00415] Clause 13. The circuit of clause 10 further comprising a
microprocessor, wherein
the meter comprises an analog to digital convertor for providing the baseline
voltage
differential between the two branches to the microprocessor and potentiometer
comprises a
digitally controlled potentiometer controlled by the microprocessor for
varying the first and
second resistances of the first and second legs of the digital potentiometer.
[00416] In some implementations, processes for manufacturing a hydrogen
sulfide filter may
be described in the following clauses or otherwise described herein and as
illustrated in Figs.
34 - 38.
[00417] CLAUSE SET D
[00418] Clause 1. A process for manufacturing a hydrogen sulfide filter for
use with a
catalytic bead gas sensor, comprising: preparing a solution of a copper
compound; applying
the solution of copper compound to a glass fiber paper; drying the glass fiber
paper;
preparing a solution of sodium borohydride; applying the solution of sodium
borohydride to
the copper compound on the glass fiber paper; and drying the glass fiber
paper.
[00419] Clause 2. The process of clause 1 wherein the copper compound is one
of copper
chloride and copper sulfate.
[00420] Clause 3. A process for manufacturing a hydrogen sulfide filter for
use with a
catalytic bead gas sensor, comprising: preparing a solution of a copper
compound; applying
the solution of the copper compound to a glass fiber paper; drying the glass
fiber paper; and
applying hydrogen in nitrogen to the glass fiber paper.
[00421] Clause 4. The process of clause 3 wherein the copper compound is one
of copper
chloride and copper sulfate.
[00422] Clause 5. A process for manufacturing a hydrogen sulfide filter for
use with a
catalytic bead gas sensor, comprising: preparing a solution of a copper
compound; preparing
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a solution of sodium borohydride; mixing the solutions of the copper compound
and sodium
borohydride; and drying the resulting metallic copper particles.
[00423] Clause 6. The process of clause 5 wherein the copper compound is one
of copper
chloride and copper sulfate.
[00424] Clause 7. A filter for use with a catalytic bead sensor, comprising:
particulate
metallic copper, wherein the sizes of the metallic copper particles are
predominantly between
1 rim and 100 nm and a substrate to support the particulate metal copper.
[00425] Clause 8. The filter of clause 7, wherein the substrate comprises at
least one of
glass fiber paper, alumina, silica, zirconia, and titanium.
[00426] Clause 9. The filter of clause 8, wherein the substrate is coated with
the particulate
metal copper.
[00427] Clause 10. A filter for use with a catalytic bead sensor, comprising:
an assembly of
particulate metallic copper dried to form a shape suitable for use as a
filter, wherein the sizes
of the metallic copper particles are predominantly between 1 nm and 100 nm.
[00428] Clause 11. A hydrogen sulfide filter for use with a catalytic bead
sensor comprising
a metal not comprising lead wherein the sensor sensitivity to methane remains
above 0.65
mV/%LEL for greater than 20,000 seconds.
[00429] Clause 12. The filter of clause 11 wherein the metal comprises a
metallic copper.
[00430] Clause 13. A hydrogen sulfide filter for use with a catalytic bead
sensor comprising
a metal not comprising lead wherein the sensor capacity to hydrogen sulfide is
greater than
550 parts per million hours.
[00431] Clause 14. The filter of clause 13 wherein the metal comprises a
metallic copper.
[00432] Clause 15. The filter of clause 13 wherein the sensor capacity to
hydrogen sulfide is
greater than 600 parts per million hours.
[00433] Clause 16. The filter of clause 13 wherein the sensor capacity to
hydrogen sulfide is
greater than 650 parts per million hours.
[00434] Clause 17. The filter of clause 13 wherein the sensor capacity to
hydrogen sulfide is
greater than 700 parts per million hours.
[00435] Clause 18. The filter of clause 13 wherein the sensor capacity to
hydrogen sulfide is
greater than 750 parts per million hours.
[00436] In some implementations, devices for determining a heat index may be
described in
the following clauses or otherwise described herein and as illustrated in
Figs. 21 - 23.
[00437] CLAUSE SET E
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[00438] Clause 1. A device for determining a heat index to which a human or a
device is
exposed, the device comprising: a housing, optionally adapted to be attached
to the human,
the housing comprising; a temperature sensor; a humidity sensor; a
microprocessor in
communication with the temperature sensor and the humidity sensor; and at
least two
microphones, the microphones arranged to provide a first and second signal,
respectively, to
the microprocessor for determining an estimated wind speed; wherein the
microprocessor,
based upon data communicated from the temperature sensor and the humidity
sensor and
from the estimated wind speed, is configured to calculate a heat index and
wherein the
microprocessor provides a notification signal to alert when the heat index is
determined to be
excessive.
[00439] Clause 2. The device of clause 1, wherein there are at least three
microphones.
[00440] Clause 3. The device of clause 1, wherein the temperature sensor,
humidity sensor
and microphones are all solid-state.
[00441] Clause 4. The device of clause 1, wherein the housing further
comprises at least one
of a portable or area environmental sensing device, a portable or area gas
sensor, a portable or
area multi-gas detection instrument, a respirator, a lighting device, a fall
arrest device, a
thermal detector, a flame detector, and a chemical, biological, radiological,
nuclear, and
explosives (CBRNE) detector.
[00442] Clause 5. The device of clause 1 wherein the housing further comprises
an
electrochemical gas sensor at least partially disposed within the housing
comprising an
electrode stack, wherein the electrode stack comprises at least one gas
permeable membrane,
at least one electrolyte absorption pad, at least one measuring electrode, at
least one counter
electrode, and at least one reference electrode, the circuit in communication
with the
microprocessor to provide a signal related to the presence of one or more
particular gases and
the microprocessor adapted to provide an alarm related to an excessive level
of one or more
of the particular gases.
[00443] Clause 6. The device of clause 1 wherein the housing further comprises
a
combustible gas sensor at least partially disposed within the housing
comprising at least one
catalytic sensing bead in a chamber, the combustible gas sensor in
communication with the
microprocessor to provide a signal related to the presence of one or more
combustible gases
and the microprocessor adapted to provide an alarm related to an excessive
level of the one or
more combustible gases.
[00444] Clause 7. The system of clause 1, wherein the wind speed is at least
one of a
maximum wind speed, an instantaneous wind speed, and an average wind speed.
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[00445] Clause 8. The system of clause 1, wherein the alert is an audible
alarm to the
human based on the calculated heat index.
[00446] Clause 9. The system of clause 1, where the alert is an electronic
communication
transmitted to a remote location based on the calculated heat index.
[00447] Clause 10. A method of protecting a human or device from exposure to
excessive
heat, comprising: providing a housing adapted to be attached to the human, the
housing
comprising; a temperature sensor; a humidity sensor; at least two microphones;
and a
microprocessor; with the microprocessor calculating a wind speed from a signal
received
from the at least two microphones; with the microprocessor calculating a heat
index based
upon data received from the temperature sensor, humidity sensor and from the
wind speed;
and providing an alert when the calculated heat index is determined to be
excessive.
[00448] Clause 11. The method of clause 10, wherein the at least two
microphones comprise
at least three microphones.
[00449] Clause 12. The method of clause 10, wherein the temperature sensor,
humidity
sensor and microphones are all solid-state.
[00450] Clause 13. The method of clause 10, wherein the microprocessor is
further
electrically connected to one of a portable or area environmental sensing
device, a portable or
area gas sensor, a portable or area multi-gas detection instrument, a
respirator, a lighting
device, a fall arrest device, a thermal detector, a flame detector, and a
chemical, biological,
radiological, nuclear, and explosives (CBRNE) detector.
[00451] Clause 14. The method of clause 10 further comprising the steps of:
providing an
electrochemical gas sensor at least partially disposed within the housing
comprising an
electrode stack, wherein the electrode stack comprises at least one gas
permeable membrane,
at least one electrolyte absorption pad, at least one measuring electrode, at
least one counter
electrode, and at least one reference electrode; providing a signal from the
electrochemical
gas sensor to the microprocessor related to the presence of one or more
particular gases; and
with the microprocessor, providing an alarm signal when the signal from the
electrochemical
gas sensor indicates an excessive level of one or more of the particular
gases.
[00452] Clause 15. The method of clause 10 further comprising the steps of:
providing a
combustible gas sensor at least partial disposed within the housing comprising
at least one
catalytic sensing bead in a chamber, providing a signal from the combustible
gas sensor to the
microprocessor related to the presence of one or more combustible gases; and
with the
microprocessor, providing an alarm signal when from the combustible gas sensor
indicates an
excessive level of one or more combustible gases.
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[00453] Clause 16. The method of clause 10, wherein the wind speed is at least
one of a
maximum wind speed, an instantaneous wind speed, and an average wind speed.
[00454] Clause 17. The method of clause 10, wherein the alert is an audible
alarm to the
human based on the calculated heat index.
[00455] Clause 18. The method of clause 10, where the alert is an electronic
communication
transmitted to a remote location based on the calculated heat index.
[00456] The methods and systems described herein may be deployed in part or in
whole
through a machine that executes computer software, program codes, and/or
instructions on a
processor. The processor may be part of a server, client, network
infrastructure, mobile
computing platform, stationary computing platform, or other computing
platform. A
processor may be any kind of computational or processing device capable of
executing
program instructions, codes, binary instructions and the like. The processor
may be or include
a signal processor, digital processor, embedded processor, microprocessor or
any variant such
as a co-processor (math co-processor, graphic co-processor, communication co-
processor and
the like) and the like that may directly or indirectly facilitate execution of
program code or
program instructions stored thereon. In addition, the processor may enable
execution of
multiple programs, threads, and codes. The threads may be executed
simultaneously to
enhance the performance of the processor and to facilitate simultaneous
operations of the
application. By way of implementation, methods, program codes, program
instructions and
the like described herein may be implemented in one or more thread. The thread
may spawn
other threads that may have assigned priorities associated with them; the
processor may
execute these threads based on priority or any other order based on
instructions provided in
the program code. The processor may include memory that stores methods, codes,
instructions and programs as described herein and elsewhere. The processor may
access a
storage medium through an interface that may store methods, codes, and
instructions as
described herein and elsewhere. The storage medium associated with the
processor for
storing methods, programs, codes, program instructions or other type of
instructions capable
of being executed by the computing or processing device may include but may
not be limited
to one or more of a CD-ROM, DVD, memory, hard disk, flash drive, RAM, ROM,
cache and
the like.
[00457] A processor may include one or more cores that may enhance speed and
performance of a multiprocessor. In embodiments, the process may be a dual
core processor,
quad core processors, other chip-level multiprocessor and the like that
combine two or more
independent cores (called a die).
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[00458] The methods and systems described herein may be deployed in part or in
whole
through a machine that executes computer software on a server, client,
firewall, gateway,
hub, router, or other such computer and/or networking hardware. The software
program may
be associated with a server that may include a file server, print server,
domain server, internet
server, intranet server and other variants such as secondary server, host
server, distributed
server and the like. The server may include one or more of memories,
processors, computer
readable transitory and/or non-transitory media, storage media, ports
(physical and virtual),
communication devices, and interfaces capable of accessing other servers,
clients, machines,
and devices through a wired or a wireless medium, and the like. The methods,
programs or
codes as described herein and elsewhere may be executed by the server. In
addition, other
devices required for execution of methods as described in this application may
be considered
as a part of the infrastructure associated with the server.
[00459] The server may provide an interface to other devices including,
without limitation,
clients, other servers, printers, database servers, print servers, file
servers, communication
servers, distributed servers and the like. Additionally, this coupling and/or
connection may
facilitate remote execution of program across the network. The networking of
some or all of
these devices may facilitate parallel processing of a program or method at one
or more
location without deviating from the scope of the disclosure. In addition, all
the devices
attached to the server through an interface may include at least one storage
medium capable
of storing methods, programs, code and/or instructions. A central repository
may provide
program instructions to be executed on different devices. In this
implementation, the remote
repository may act as a storage medium for program code, instructions, and
programs.
[00460] The software program may be associated with a client that may include
a file client,
print client, domain client, interne client, intranet client and other
variants such as secondary
client, host client, distributed client and the like. The client may include
one or more of
memories, processors, computer readable transitory and/or non-transitory
media, storage
media, ports (physical and virtual), communication devices, and interfaces
capable of
accessing other clients, servers, machines, and devices through a wired or a
wireless medium,
and the like. The methods, programs or codes as described herein and elsewhere
may be
executed by the client. In addition, other devices required for execution of
methods as
described in this application may be considered as a part of the
infrastructure associated with
the client.
[00461] The client may provide an interface to other devices including,
without limitation,
servers, other clients, printers, database servers, print servers, file
servers, communication
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servers, distributed servers and the like. Additionally, this coupling and/or
connection may
facilitate remote execution of program across the network. The networking of
some or all of
these devices may facilitate parallel processing of a program or method at one
or more
location without deviating from the scope of the disclosure. In addition, all
the devices
attached to the client through an interface may include at least one storage
medium capable of
storing methods, programs, applications, code and/or instructions. A central
repository may
provide program instructions to be executed on different devices. In this
implementation, the
remote repository may act as a storage medium for program code, instructions,
and programs.
[00462] The methods and systems described herein may be deployed in part or in
whole
through network infrastructures. The network infrastructure may include
elements such as
computing devices, servers, routers, hubs, firewalls, clients, personal
computers,
communication devices, routing devices and other active and passive devices,
modules and/or
components as known in the art. The computing and/or non-computing device(s)
associated
with the network infrastructure may include, apart from other components, a
storage medium
such as flash memory, buffer, stack, RAM, ROM and the like. The processes,
methods,
program codes, instructions described herein and elsewhere may be executed by
one or more
of the network infrastructural elements.
[00463] The methods, program codes, and instructions described herein and
elsewhere may
be implemented on a cellular network having multiple cells. The cellular
network may either
be frequency division multiple access (FDMA) network or code division multiple
access
(CDMA) network. The cellular network may include mobile devices, cell sites,
base stations,
repeaters, antennas, towers, and the like.
[00464] The methods, programs codes, and instructions described herein and
elsewhere may
be implemented on or through mobile devices. The mobile devices may include
navigation
devices, cell phones, mobile phones, mobile personal digital assistants,
laptops, palmtops,
netbooks, pagers, electronic books readers, music players and the like. These
devices may
include, apart from other components, a storage medium such as a flash memory,
buffer,
RAM, ROM and one or more computing devices. The computing devices associated
with
mobile devices may be enabled to execute program codes, methods, and
instructions stored
thereon. Alternatively, the mobile devices may be configured to execute
instructions in
collaboration with other devices. The mobile devices may communicate with base
stations
interfaced with servers and configured to execute program codes. The mobile
devices may
communicate on a peer to peer network, mesh network, or other communications
network.
The program code may be stored on the storage medium associated with the
server and
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executed by a computing device embedded within the server. The base station
may include a
computing device and a storage medium. The storage device may store program
codes and
instructions executed by the computing devices associated with the base
station.
[00465] The computer software, program codes, and/or instructions may be
stored and/or
accessed on machine readable transitory and/or non-transitory media that may
include:
computer components, devices, and recording media that retain digital data
used for
computing for some interval of time; semiconductor storage known as random
access
memory (RAM); mass storage typically for more permanent storage, such as
optical discs,
forms of magnetic storage like hard disks, tapes, drums, cards and other
types; processor
registers, cache memory, volatile memory, non-volatile memory; optical storage
such as CD,
DVD; removable media such as flash memory (e.g. USB sticks or keys), floppy
disks,
magnetic tape, paper tape, punch cards, standalone RAM disks, Zip drives,
removable mass
storage, off-line, and the like; other computer memory such as dynamic memory,
static
memory, read/write storage, mutable storage, read only, random access,
sequential access,
location addressable, file addressable, content addressable, network attached
storage, storage
area network, bar codes, magnetic ink, and the like.
[00466] The methods and systems described herein may transform physical and/or
or
intangible items from one state to another. The methods and systems described
herein may
also transform data representing physical and/or intangible items from one
state to another.
[00467] The elements described and depicted herein, including in flow charts
and block
diagrams throughout the figures, imply logical boundaries between the
elements. However,
according to software or hardware engineering practices, the depicted elements
and the
functions thereof may be implemented on machines through computer executable
transitory
and/or non-transitory media having a processor capable of executing program
instructions
stored thereon as a monolithic software structure, as standalone software
modules, or as
modules that employ external routines, code, services, and so forth, or any
combination of
these, and all such implementations may be within the scope of the present
disclosure.
Examples of such machines may include, but may not be limited to, personal
digital
assistants, laptops, personal computers, mobile phones, other handheld
computing devices,
medical equipment, wired or wireless communication devices, transducers,
chips, calculators,
satellites, tablet PCs, electronic books, gadgets, electronic devices, devices
having artificial
intelligence, computing devices, networking equipment, servers, routers and
the like.
Furthermore, the elements depicted in the flow chart and block diagrams or any
other logical
component may be implemented on a machine capable of executing program
instructions.
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Thus, while the foregoing drawings and descriptions set forth functional
aspects of the
disclosed systems, no particular arrangement of software for implementing
these functional
aspects should be inferred from these descriptions unless explicitly stated or
otherwise clear
from the context. Similarly, it will be appreciated that the various steps
identified and
described above may be varied, and that the order of steps may be adapted to
particular
applications of the techniques disclosed herein. All such variations and
modifications are
intended to fall within the scope of this disclosure. As such, the depiction
and/or description
of an order for various steps should not be understood to require a particular
order of
execution for those steps, unless required by a particular application, or
explicitly stated or
otherwise clear from the context.
[00468] The methods and/or processes described above, and steps thereof, may
be realized
in hardware, software or any combination of hardware and software suitable for
a particular
application. The hardware may include a dedicated computing device or specific
computing
device or particular aspect or component of a specific computing device. The
processes may
be realized in one or more microprocessors, microcontrollers, embedded
microcontrollers,
programmable digital signal processors or other programmable device, along
with internal
and/or external memory. The processes may also, or instead, be embodied in an
application
specific integrated circuit, a programmable gate array, programmable array
logic, or any
other device or combination of devices that may be configured to process
electronic signals.
It will further be appreciated that one or more of the processes may be
realized as a computer
executable code capable of being executed on a machine readable medium.
[00469] The computer executable code may be created using a structured
programming
language such as C, an object oriented programming language such as C++, or
any other
high-level or low-level programming language (including assembly languages,
hardware
description languages, and database programming languages and technologies)
that may be
stored, compiled or interpreted to run on one of the above devices, as well as
heterogeneous
combinations of processors, processor architectures, or combinations of
different hardware
and software, or any other machine capable of executing program instructions.
[00470] Thus, in one aspect, each method described above and combinations
thereof may be
embodied in computer executable code that, when executing on one or more
computing
devices, performs the steps thereof. In another aspect, the methods may be
embodied in
systems that perform the steps thereof, and may be distributed across devices
in a number of
ways, or all of the functionality may be integrated into a dedicated,
standalone device or other
hardware. In another aspect, the means for performing the steps associated
with the processes
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described above may include any of the hardware and/or software described
above. All such
permutations and combinations are intended to fall within the scope of the
present disclosure.
[00471] While the disclosure has been disclosed in connection with the
preferred
embodiments shown and described in detail, various modifications and
improvements
thereon will become readily apparent to those skilled in the art. Accordingly,
the spirit and
scope of the present disclosure is not to be limited by the foregoing
examples, but is to be
understood in the broadest sense allowable by law.
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