Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: METHOD, DEVICE AND APPARATUS FOR MONITORING HALOGEN
LEVELS IN A BODY OF WATER
FIELD OF THE INVENTION
The present invention relates generally to the monitoring of halogen levels in
bodies of water,
and more specifically, to a method, device and system for monitoring halogen
levels, including
for example monitoring bromine and/or chlorine levels, in a body of water,
such as in bathing
units (e.g. pools, spas, etc..) and the like.
BACKGROUND
A bathing unit, such as for example a spa or pool, typically includes various
components used in
the operation of the bathing unit system such as a water holding receptacle,
pumps to circulate
water in a piping system, a heating module to heat the water, a filter system,
an air blower, a
lighting system, and a control system for activating and managing the various
parameters of the
bathing unit components. The circulation system pumps water from the water
holding receptacle
through the filter system to maintain the body of water at sanitary
conditions. In particular, the
water passes through the filter system to reduce the accumulation of foreign
material, such as
hair, soil, or solids, in the pool or spa.
In addition to filtering, bathing unit systems also require regular
sanitization in order to maintain
hygienic conditions. Allowing sanitation agent levels to either fall below or
rise above required
levels may result in decreased efficiency of the system. Low levels of
chemical sanitizer in the
bathing unit can contribute to algae blooms, bacterial breakouts, cloudiness
in the water, and
chemical imbalances. If left untreated, water-borne bacteria can afflict users
of the bathing units
with a variety of health problems and illnesses, such as pseudomonas, rashes,
hot tub lung, ear
infections, etc.
Water sanitation is well known and long practiced. Typical sanitation regimens
and processes
rely on halogen treatment chemicals to provide disinfecting action. Halogens,
and in particular
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free chlorine and bromine, have recently been the chemicals of choice for
treating recreational
reservoir water.
Conventional halogen-based systems, to be effective, require that the
concentration of halogen
(chlorine or bromine for example) be maintained within a specified range,
which is typically
between 3ppm (parts per million) and 5ppm. Maintaining a suitable
concentration of halogen in
the bathing unit typically requires the user to perform periodic measurements
for example by
using water testing kits and then taking action to adjust the concentration of
the sanitation
species so that it lies within the desired specified concentration range.
Using these
measurements, the user may for example add water to reduce the concentration
of halogen and/or
may cause an action to take place to increase the concentration of halogen
(e.g. by controlling an
electrolytic cell to increase the generation of halogen). This is a lengthy
process which is not
always diligently followed by the user, often resulting in less than ideal
water conditions.
To address such deficiencies, various automated devices for measuring the
concentration of
halogen (chlorine or bromine for example) have been proposed.
U.S. Patent No. 4,752,740 ("the '740 Patent") proposes a water chemistry
analysis device for
pools, spas, and the like which includes an oxidation-reduction potential
(ORP) probe and/or a
pl 1 (PH) probe disposed in the recirculation/filtration system. The contents
of the
aforementioned document are incorporated herein by reference. The ORP probe
generates an
electrical signal directly related to the active form of a sanitizer contained
in the water while the
PH probe generates and electrical signal that is related to the
acidity/basicity level of the water.
The signals are used to display information conveying measured ORP levels
against upper and
lower limits corresponding to "more than necessary" and "less than necessary"
levels of sanitizer
in the water and to convey measured PH levels against upper and lower limits
corresponding to
"lower acidity than optimum" and "higher acidity than optimum" levels of
water.
A deficiency associated with devices of the type described in the '740 Patent
is that the ORP
probe and the PH probe are physical probes that are in contact with the water
of the bathing unit.
These physical probes are prone to mechanical wear and tear and deposits on
the physical
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probes, which naturally occur in bathing unit environment, often affect the
precision of the
measurements taken and require frequent calibration.
Another approach that has been proposed more recently, and which may reduce or
eliminate the
need for physical probes in the water of the receptacle, is to make use of UV
spectrometry to
measure the concentration of halogen in spas. Generally, the approach includes
emitting a light at a
specific wavelength through a sample of water and measuring the level of
absorption as the light
travels through the sample of water. Most chemical compounds absorb light in a
manner that varies
according to the wavelengths of the light used and the amount of the chemical
compound present.
The measured level of absorption is used in combination with the spectral
signature of the halogen
sought to be measured to derive a concentration of the halogen in that sample
of water. While in
theory such approach may appear simple, in practical bathing unit applications
the concentrations of
halogen being measured are low and the difference between a suitable
concentration of halogen and
one that is unsuitable is small. As a result, variations in extraneous factors
unrelated to the
concentration of the halogen in the water may in some cases materially
influence the precision of the
measurements obtained rendering them unsuitable for distinguishing between a
suitable
concentration of halogen and one that is unsuitable.
U.S. Patent No. 8,212,222 ("the '222 Patent") proposes a method of measuring
chlorine
concentration in a solution that aims to compensate for a specific one of
these extraneous factors,
namely the effect of temperature on the precision of the measurements. More
specifically, the '222
Patent proposes a method of measuring chlorine concentration in a solution by
making first and
second measurements of transmission of ultraviolet light at a selected
wavelength through respective
first and second samples of the solution held in a "cuvette", where the first
and second solution
samples are heated to different temperatures. More specifically, the approach
proposed by the '222
Patent exploits the variability in the equilibrium point of HOCl/OC1¨ with
temperature and is
premised on the absorption spectra of strongly ionised salts, such as nitrates
and carbonates
dissolved in solution, not changing with temperature. By taking the difference
(absolute difference
or ratio) from a single wavelength, for example, at 293 nanometers (nm) (the
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absorption peak of the 0C1¨ species) at two different temperatures, a
measurement of the level
of OC1¨ that is less sensitive to water temperature can be derived.
A deficiency with methods and devices of the type described in the '222 Patent
is that they
require a complex arrangement including a valve arrangement to place
sequential samples of the
solution in a "cuvette", a heat exchanger to heat one of the samples and not
the other, and
components for sequentially taking measurements of the samples to obtain two
absorption
measurements. The complexity of the arrangement proposed in the '222 Patent
including the
requirement to provide a valve system and a heat exchanger, adds cost to the
device. Moreover,
the valve arrangement, which includes mechanically moving parts, is prone to
mechanical wear
and tear, which may reduce the useful life of the arrangement.
Another deficiency with methods and devices of the type described in the '222
Patent is that
while the solution proposed may potentially compensate for water temperature
effects, the
precision of the measurements remains sensitive to other extraneous factors
unrelated to the
concentration of the halogen. While controlled environments (such as
laboratories) may make it
possible to achieve suitable levels of precision even at low levels of halogen
concentration by
eliminating variations of certain extraneous factors, achieving such level of
control is not suitable
for practical bathing unit environments.
Against the background described above, there is a need in the industry to
provide a method,
device and system for monitoring halogen levels in bathing units that
alleviate at least in part the
problems associated with existing methods, devices and systems.
SUMMARY
In accordance with a first general aspect, an apparatus is proposed for
monitoring a concentration
of a specific halogen in water. The apparatus comprises:
a, a housing;
b. an optical absorption analyzer positioned within said housing, said optical
absorption
analyzer being configured for:
i. making a first measurement of transmission of ultraviolet light from a
light
source through a sample of water, said light source emitting light at a
specific
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wavelength, wherein the specific wavelength of the light source is selected at
least in part based on the specific halogen whose concentration is being
monitored;
ii. making a second measurement of transmission of ultraviolet light from said
light source, wherein the second measurement is taken prior to the ultraviolet
light travelling through the sample of water;
iii. deriving the concentration of the specific halogen at least in part by
processing
results of the first and the second measurements;
iv. releasing a signal conveying the derived concentration of the specific
halogen.
In accordance with a specific practical implementation, the optical absorption
analyzer may
comprise a first detector for making the first measurement of transmission of
ultraviolet light
from the light source through the sample of water and a second detector for
making the second
measurement of transmission of ultraviolet light from the light source prior
to the ultraviolet light
travelling through the sample of water. The optical absorption analyzer may
also comprise a
beam splitter module for directing a first part of ultraviolet light generated
by the light source
toward the first detector through the sample of water and a second part of
ultraviolet light
generated by the light source toward the second detector. The optical
absorption analyzer may
also comprise a processor in communication with the first and second detector
configured for
deriving the concentration of the specific halogen at least in part by
processing the results of the
first and the second measurements.
Advantageously, the use of first and second measurements of transmission of
ultraviolet light in
the proposed apparatus described above to derive the concentration of the
specific halogen may
allow compensating for effects that may be attributable to variations in the
ultraviolet light
emitted by light source rather than those that may be attributable to actual
concentration of
halogen. It is to be appreciated that variations in the ultraviolet light
emitted by light source may
be due, for example but without being limited to, the variations that occurred
in the
manufacturing of the light source as well as variations that occur over time
as the light source
.. ages.
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Optionally, in some implementations, the apparatus may further comprise a
temperature sensor
for generating a signal conveying water temperature information for the sample
of water. In such
implementations, the optical absorption analyzer may be configured for
deriving the
concentration of the specific halogen at least in part by processing the
results of the first and the
second measurements and the water temperature information. Advantageously, the
use of the
water temperature information in the proposed apparatus described above to
derive the
concentration of the specific halogen may allow compensating for effects that
may be
attributable to variations in water temperature rather than those that may be
attributable to actual
concentration of halogen.
In some specific practical implementations, the apparatus may be configured
for monitoring a
specific halogen amongst different halogen types by using a light source
suitable for the specific
halogen. Halogen types frequently used in bathing units for example may
include chlorine and
bromine.
For example, in some specific applications in which the specific halogen whose
concentration is
being monitored is bromine, the specific wavelength at which the light source
used emits light is
between 280nm and 380nm. In some specific implementations, the specific
wavelength at which
.. the light source used emits light may be between 300nm and 360nm. In a non-
limiting practical
implementation, the specific wavelength at which the light source used emits
light is about
310nm. In another non-limiting practical implementation, the specific
wavelength at which the
light source used emits light is about 330nm.
In some implementations, the light source may be a first light source emitting
light at a first
specific wavelength. The optical absorption analyzer may further be configured
for making a
first measurement of transmission of light from a second light source through
the sample of
water, the second light source emitting light at a second specific wavelength
different from the
first specific wavelength. The optical absorption analyzer may also be
configured for making a
second measurement of transmission of light from the second light source,
wherein the second
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measurement is taken prior to the light from the second light source
travelling through the
sample of water. The optical absorption analyzer is configured to derive the
concentration of the
specific halogen by processing at least results of the first and the second
measurements of
transmission of light from the second light source and the results of the
first and the second
measurements of transmission of light from the first light source.
In some specific practical implementations, the same detector may be used for
making the first
measurements of transmission of light from the first and second light sources
through the sample
of water and the same second detector may be used for making the second
measurements of
transmission of light from the first and second light sources prior to the
light travelling through
the sample of water. In addition, the same beam splitter module as that used
from the first light
source may be used for directing a first part of light generated by the second
light source toward
the first detector through the sample of water and a second part of light
generated by the second
light source toward the second detector.
In some specific practical implementations, the second light source emits
light at a wavelength
that is generally unaffected by the concentration of the halogen in the sample
of water. In a non-
limiting implementation, the second light source transmits at a wavelength
that is in the visible
range of the spectrum. For example, the second specific wavelength at which
the second light
.. source emits light may be between about 450nm and 1 l 00nm. In some
specific implementations,
the second specific wavelength at which the second light source emits light is
between about
475nm and 550nm. In a non-limiting practical implementation, the second
specific wavelength at
which the second light source emits light is about 500nm.
Advantageously, the use of measurements of transmission of ultraviolet light
of first and second
light sources emitted lights at different wavelengths in the proposed
apparatus described above
may allow compensating for effects that may be attributable to impurities in
an optical path
between the first light source and the first detector rather than those that
may be attributable to
actual concentration of the halogen in the sample of water. It is to be
appreciated that impurities
in the optical path between the first light source and the first detector may
be due to, for example
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but without being limited to, sand particles in the sample of water and/or
particles having
adhered to walls of a cuvette between the first light source and the first
detector wherein the
cuvette holds the sample of water.
In some specific practical applications, the first and second light sources
may be sequentially
turned "ON" and "OFF", wherein the light source emits light when it is "ON"
and does not emit
light when it is "OFF", so that in turn measurements may be made by the
detectors.
Alternatively, the first and second light sources may be continuously left
"ON" and may be
operated according to an intermittent light pattern, such as for example, but
without being limited
to, sinusoidal light patterns.
Advantageously, keeping the first and second light sources "ON" and operating
them according
to an intermittent (e.g., a periodic) light pattern may present a number of
advantages including
reducing transition effects caused by activating the light sources.
In a specific practical application, the first light source emits light at a
first frequency and the
second light source emits light at a second frequency, wherein the first
frequency is different
from the second frequency. The optical absorption analyzer of the apparatus is
configured for
deriving the concentration of the specific halogen at least in part based on a
frequency
distribution associated with:
¨ the results of the first and the second measurements of the transmission
of light from
the first light source; and
¨ the results of the first and the second measurements of the transmission
of light from
the second light source.
In some specific practical applications, the first and second frequencies may
be chosen so that
they are not harmonics of one another. In a specific non-limiting example of
implementation, the
first light source may have a first frequency between 420 and 580Hz, such as
for example about
450Hz. The second light source may have a second frequency above 350Hz such as
for example
about 570Hz.
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Advantageously, by selecting certain first and second frequencies. the effects
of external
interferences may be reduced on the measurements of the transmission of light
from the first and
second light sources. External interferences may include, for example but
without being limited
to, changes in ambient light (for example due to the time of day, the amount
of sun, the type of
light, clouds, etc.) as well as the presence of electromagnetic (EM) fields
(typically caused by
the electrical grid emitting EM fields at 60Hz, 120Hz and harmonics (240Hz,
480Hz, etc.)). In a
specific example, the first and second frequencies of the light sources may be
chosen to be
sufficiently high so that a high pass filter can be used to filter out effects
of changes in ambient
.. light, which would typically be at relatively low frequencies. In addition,
a suitable filter, such as
a band-pass filter, may be used to filter out effects of the
electrical/electronic signals without
hindering the first and second frequencies of the first and second light
sources. In such cases, the
first and second frequencies of the light sources may be chosen not to
correspond to a harmonic
of the electrical/electronic signals.
In some specific implementations, the housing of the apparatus may have walls
at least partially
made of a material permeable to ultraviolet light defining opposing windows
for allowing
transmission of ultraviolet through the sample of water from a light source to
a detector. Any
suitable material may be used such as, for example but without being limited
to, quartz and/or
.. suitable types of optical glass.
In specific practical implementations of the apparatus, the housing may have
different
configurations.
In specific implementations of a first type, the housing is configured to be
connected to
circulation piping of a bathing unit including at least one circulation pump.
When the housing is
connected to the circulation piping of the bathing unit, the housing is in
fluid communication
with the circulation piping so that water from a receptacle of the bathing
unit is circulated
through a space within the housing.
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In specific implementations of a second type, the housing is a free-standing
device configured to
float on top of the water held in a receptacle of a bathing unit. The housing
may have a lower
portion configured for being at least partially submerged in water during use
and an upper
portion configured for extending at least partially above the level of the
water in the bathing unit
during use. The lower portion includes walls extending into the water and
defining spaced apart
opposing windows made at least in part of a material permeable to ultraviolet
light, the sample of
water being between the spaced apart opposing windows. Optionally, the upper
portion of the
housing may include a user interface device, including but not limited to a
display screen, in
electronic communication with the optical absorption analyzer for displaying
information
derived from the derived concentration of the specific halogen.
Optionally, the apparatus may comprise an antenna for transmitting a signal
conveying the
derived concentration of the specific halogen to a remote device, such as a
smart phone,
computing device and/or bathing unit controller for example. The remote device
may include a
.. processing unit and a display for conveying the derived concentration of
the specific halogen
and/or for processing the derived concentration of the specific halogen to
derive control signals
for controlling the operations of one or more devices in order to adjust the
concentration of
halogen in the bathing unit. In a non-limiting example, the control signals
are configured for
controlling operation of an electrolytic cell to adjust the amount of halogen
being generated.
Alternatively, or in addition, the control signals may be configured for
controlling operation of
one or more valves for adding water to the bathing unit to reduce the
concentration of halogen.
In accordance with another aspect, a method is provided for monitoring a
concentration of a
specific halogen in water. The method comprises:
- making a first measurement of transmission of ultraviolet light from a light
source
through a sample of water, said light source emitting light at a specific
wavelength,
wherein the specific wavelength of the light source is selected at least in
part based on
the specific halogen whose concentration is being monitored;
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¨ making a second measurement of transmission of ultraviolet light from
said light
source, wherein the second measurement is taken prior to the ultraviolet light
travelling through the sample of water;
¨ deriving the concentration of the specific halogen at least in part by
processing results
of the first and the second measurements;
¨ releasing a signal conveying the derived concentration of the specific
halogen.
In some specific implementations, the method may also comprise generating a
signal conveying
water temperature information for the sample of water and deriving the
concentration of the
specific halogen at least in part by processing the results of the first and
the second
measurements and the water temperature information.
In some specific implementations, the light source may be a first light source
and the specific
wavelength may be a first specific wavelength, and the method may further
comprise:
a. making a first measurement of transmission of light from a second light
source through
the sample of water, said second light source emitting light at a second
specific
wavelength, wherein the second specific wavelength is different from the first
specific
wavelength;
b. making a second measurement of transmission of light from said second light
source,
wherein the second measurement is taken prior to the light travelling through
the sample
of water;
wherein the concentration of the specific halogen is derived by processing at
least:
i. results of the first and the second measurements of transmission of
light
from said second light source; and
ii. the results of the
first and the second measurements of transmission of
light from said first light source.
Optionally, the first light source may emit light at a first frequency and the
second light source
may emit light at a second frequency, wherein the first frequency is different
from the second
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frequency. The method may comprise deriving the concentration of the specific
halogen at least
in part based on a frequency distribution associated with:
a. the results of the first and the second measurements of the
transmission of light from said
first light source; and
b. the results of the first and the second measurements of the transmission of
light from said
second light source.
Optionally still, the method may comprise transmitting a signal conveying the
derived
concentration of the specific halogen to a remote device, the remote device
including a display
for conveying the derived concentration of the specific halogen.
Alternatively, or in addition, the
method may comprise transmitting the signal conveying the derived
concentration of the specific
halogen to a processing module configured for using the derived concentration
of the specific
halogen to control generation of specific halogen for a bathing unit.
In accordance with another aspect, a device for monitoring a concentration of
a specific halogen
in a bathing unit is provided. The device comprises a housing configured for
floating atop a body
of water held in a receptacle of the bathing unit, the housing having a lower
portion configured
for being at least partially submerged in water during use and an upper
portion configured for
extending at least partially above the water, the lower portion including
walls extending into the
body of water and defining spaced apart opposing windows made at least in part
of a material
permeable to ultraviolet light. The device also comprises an optical
absorption analyzer
positioned within the housing. The optical absorption analyzer is configured
for making a
measurement of transmission of ultraviolet light from a light source through a
sample of water
between the spaced apart opposing windows, the light source emitting light at
a specific
wavelength, wherein the specific wavelength of the light source is selected at
least in part based
on the specific halogen whose concentration is being monitored. The optical
absorption analyzer
is also configured for deriving the concentration of the specific halogen at
least in part by
processing results of the measurement of transmission of ultraviolet light
from the light source
through the sample of water and for releasing a signal conveying the derived
concentration of the
specific halogen.
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All features of embodiments which are described in this disclosure and are not
mutually
exclusive can be combined with one another. Elements of one embodiment can be
utilized in the
other embodiments without further mention.
Other aspects and features of the present invention will become apparent to
those ordinarily
skilled in the art upon review of the following description of specific
embodiments in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the embodiments of the present invention is provided
herein below, by
way of example only, with reference to the accompanying drawings, in which:
Figure 1 is a diagram of a bathing unit system incorporating a water analysis
device for
monitoring a concentration of a specific halogen in water in accordance with a
specific example
of implementation;
Figures 2A and 2B are diagrams of a water analysis device suitable for use in
a bathing unit
system of the type shown in Figure 1, wherein the water analysis device is
configured in
accordance with a free-standing type of implementation;
Figure 3 shows a water analysis device of the type shown in Figures 2A and 2B
positioned to
float on a body of water, the device including an optical absorption analyzer
in accordance with a
first specific implementation;
Figure 4 is a functional block diagram of a water analysis device suitable for
use in a bathing unit
system of the type shown in Figure 1, wherein the water analysis device is
configured in
accordance with an in-line type of implementation and includes an optical
absorption analyzer
similar to that shown in Figure 3;
Figure 5A is a functional block diagram showing transmission of a signal by
the optical
absorption analyzer of the device of Figure 3 or the optical absorption
analyzer of Figure 4 to a
remote computing device;
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Figure 5B is functional block diagram showing transmission of a signal by the
optical absorption
analyzer of the device of Figure 3 or the optical absorption analyzer of
Figure 4 to a controller of
the bathing unit system of Figure 1;
Figure SC is a functional block diagram showing transmission of a signal by
the optical
absorption analyzer of the device of Figure 3 to a user interface part of the
device of Figure 3;
Figure 6 shows a functional block diagram of a bathing unit system including a
water circulation
path in which a water analysis device of the type shown in Figure 4 has been
positioned in-line in
accordance with a non-limiting implementation of the invention;
Figure 7 is a diagram of a first variant of the in-line type of water analysis
device shown in
Figure 4, wherein the water analysis device includes an optical absorption
analyzer in accordance
with a second specific implementation;
Figure 8 is a diagram of a second variant of the in-line type of water
analysis device shown in
Figure 4, wherein the water analysis device includes an optical absorption
analyzer in accordance
with a third specific implementation;
Figure 9 is a diagram of a third variant of the in-line type of water analysis
device shown in
Figure 4, wherein the water analysis device includes an optical absorption
analyzer in accordance
with a fourth specific implementation:
Figure 10 is a block diagram, showing some functional modules of a processing
unit that may be
used in connection with the water analysis device shown in Figures 3, 4, 7, 8
and 9 in accordance
with non-limiting examples of implementation of the invention;
Figure 11 shows a functional diagram of components of a water analysis device
using alternating
light sources in accordance with a variant of implementation of the water
analysis device shown
in Figure 9;
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Figures 12A and 12 B show graph of a frequency domain representation of light
signals received
at detector of the device of Figure 9 and implemented in accordance with the
variant depicted in
Figure 11;
Figure 13 shows a simplified representation of a user interface device of the
device of Figure 3 in
accordance with a non-limiting example of implementation;
Figure 14 shows an example of an embodiment in which the device of Figure 3 is
part of a
communication network according to a non-limiting example;
Figures 15A and 15B show different examples of shapes of a space in a lower
portion of a
housing of the device of Figure 3 in which a sample of water is received;
Figure 16 shows an example of a lookup table that may be stored in a memory of
a processing
unit of the water analysis devices of the type shown in Figures 3, 7, 8 and 9
and/or in a memory
of a bathing unit controller of the type depicted in Figure 1;
Figure 17 shows an example of an embodiment of a water analysis device in
which a power
source comprises a solar panel in accordance with a non-limiting example of
implementation;
and
Figure 18 shows a non-limiting example of a physical embodiment of the water
analysis device
of Figures 4, 7, 8 and 9.
It will be noted that throughout the appended drawings, like features are
identified by like
reference numerals.
In the drawings, the embodiments of the invention are illustrated by way of
examples. It is to be
expressly understood that the description and drawings are only for the
purpose of illustration
and are an aid for understanding. They are not intended to be a definition of
the limits of the
invention.
DETAILED DESCRIPTION
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The description below is directed to specific implementations and uses of
embodiments of the
invention in the context of bathing units. It is to be understood that the
term "bathing unit", as
used for the purposes of the present description, refers to spas/swim-spas,
whirlpools, hot tubs,
bath tubs, therapeutic baths and swimming pools and any other type of unit
having a water
receptacle holding water in which a halogen has been dissolved. Moreover, it
is to be appreciated
that while specific embodiments of the invention have been described for using
in the context of
bathing units, the person skilled in the art will appreciate in view of the
present description that
alterative embodiments may be configured for use in an environment including a
body of water
other than a bathing unit in which measurement of a concentration of halogen
may be of interest.
Figure 1 illustrates a block diagram of a bathing unit system 100
incorporating a water analysis
device 500 in accordance with a specific example of implementation. The
bathing unit system
100 includes a bathing unit receptacle 102 for holding water 104, water inlets
110 (only one is
shown) which will typically be connected to respective jets, water outlets 108
(only one is
shown) and a circulation system 106 including a flow conduit for removing and
returning water
from and to the receptacle 102 through the water inlets and water outlets. The
circulation system
106 depicted is shown as having a single flow conduit for the purpose of
simplicity, however, the
person skilled in the art will appreciate that practical implementations of
the bathing unit system
100 may include multiple flow conduits interconnecting water inlets and water
outlets of the
receptacle 102. A heating module 116, a water pump 112 and a filter 124 are
shown positioned
within the circulation system 106. It should be understood that the bathing
unit 100 may include
more or fewer bathing unit components that may be positioned in various
suitable positions in
the circulation system. The bathing unit system 100 may further include a
sanitizing system 130
for sanitizing the water 104 in the receptacle 102. In some embodiments, the
sanitizing system
130 may comprise an electrolytic cell 135 configured to release a free halogen
in the water of the
bathing unit 100.
A bathing unit controller 122 controls the settings of the components of the
bathing unit system
100 including the settings of the heating module 116, the water pump 112, the
filter 124 and/or
the sanitizing system 130. The controller 122 receives electrical power from
an electric power
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source (not shown) and controls the distribution of power supplied to the
various bathing unit
components on the basis of control signals originating from various sensors,
program
instructions and/or user commands in order to cause desired operational
settings to be
implemented. Some manners in which the bathing unit controller 122 may be
configured and
used to control the bathing unit components for the regulation of the
operation of the bathing unit
system 100 are generally known in the art and are not critical to the
invention and as such will
not be described in further detail here.
As depicted in Figure 1, a water analysis device 500 may be used in connection
with the bathing
unit system 100. More specifically, the water analysis device 500 is
configured to monitor a
concentration of a specific halogen H in the water of the bathing unit system
100 to assist in
maintaining such concentration within a desired operational range. To that
end, the water
analysis device 500 comprises an optical absorption analyzer 150 and a housing
502 within
which the optical absorption analyzer 150 is disposed. The halogen H whose
concentration is
monitored may be any suitable halogen. For instance, in this embodiment, the
halogen H is
bromine. However, in other embodiments, the specific halogen H may be chlorine
or any other
suitable halogen. It is noted that in this description, the term "halogen" may
also refer to
chemical species containing halogens rather than pure elements, for instance
hypochlorous
and/or hypobromous acid.
The water analysis device 500 may be embodied in different types of
configurations.
"Standalone" configuration of water analysis device 500
In a first type of configuration, shown in Figures 2A, 2B and 3, the water
analysis device 500 is a
standalone device configured to be disposed in the water 104 contained in the
receptacle 102 of
the bathing unit system 100 of Figure 1. The water analysis device 500 is a
"standalone" device
in that it is structurally separate from the other components of the bathing
unit 100 (e.g., the
circulation system 106). More specifically, in this embodiment, the housing
502 is configured to
.. float atop the water 104 held in the receptacle 102 such that an upper part
of the housing 502
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remains above a level of the water 104 and a lower part of the device is
submersed below the
water level when the analysis device 500 is disposed in the receptacle 102. In
this specific
example of implementation, the housing 502 comprises a lower portion 512
configured for being
at least partially submerged in water during use and an upper portion 514
configured for
extending at least partially above the water 104 held in the receptacle 102
during use. This may
be achieved for example by ensuring that the housing 502 has a density that is
less than a density
of the water 104 in the receptacle.
The lower portion 512 of the housing 502 comprises a pair of opposing walls
508 510 which in
use extend into the water 104 of the receptacle and which define a space 504
there between
where water can circulate. The walls 508 510 include opposing windows 516 518
spaced apart
by a distance Dw and which are made of a material permeable to ultraviolet
light such as, for
example, quartz, suitable types of optical glass, plastic (e.g., cellulose
diacetate, polyethylene,
acrylic, polyester, etc.) or any other suitable material.
In the specific example of implementation depicted in Figures 2A 2B and 3, the
housing 502 is
configured such that the space 504 of the lower portion 512 of the housing 502
is substantially
U-shaped. However, the space 504 defined by the walls 508 510 of the housing
502 may be
shaped differently in other examples. For instance, in other examples. the
space 504 defined by
.. the walls 508, 510 may be V-shaped, cylindrical, or may have any other
suitable shape. Figures
15A and 15B show yet other non-limiting configurations that may be formed by
the walls 508
510 of the housing 502. For instance, Figure 15A shows a specific example of
implementation in
which the lower portion 512 of the housing 502 comprises a pair of projections
515 517
projecting from a bottom surface 519 of the housing 502 and which define the
walls 508 510. In
this example, the projections 515 517 extend longitudinally along a
substantial portion of a width
WH of the housing 502. Notably, the projections 515 517 extend substantially
from one side of a
periphery of the housing 502 to an opposite side of the periphery of the
housing 502. Figure 15B
shows another specific example of implementation in which the projections 515
517 extend
longitudinally along a limited portion of the width WH of the housing 502. For
example, in some
.. cases, a ratio of a length Lp of each projection 515 517 over the width W11
of the housing 502
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may be no more than 80%, in some cases no more than 70%, in some cases no more
than 50%,
and in some cases even less. The projections 515 517 may contain components of
the optical
absorption analyzer 150, including but not limited to the light source 152 and
the detector 156.
While the embodiment depicted in Figure 3 shows a standalone device configured
to float on the
water 104, in alternative implementations (not shown in the figures) the
standalone device may
be entirely submerged in the water during use (e.g., by being anchored to a
structure of the
receptacle 102 or by having a sufficiently high density). In such cases, both
the lower and upper
portions 512. 514 of the housing 502 may be submerged in the water. In some
cases, the water
analysis device 500 may even be configured to be disposed at a bottom of the
receptacle 102.
Optionally, with reference to Figure 2A and 13, the upper portion 514 of the
housing 502 may
comprise a user interface device 524 configured for outputting information to
a user and, in some
cases, receiving inputs from the user. For instance, in the example of
implementation depicted in
Figure 13, the user interface device 524 is configured to display information
related to results
obtained by the optical absorption analyzer 150. To that end, the user
interface device 524
comprises a display 526 (e.g., a screen) which may convey one or more
information elements
related to results obtained by the optical absorption analyzer 150 related to
a concentration of a
specific halogen in the water. In some implementations, the user interface
device 524 may
comprise user data entry module 527 for receiving inputs from the user (shown
schematically in
Figure 10) which may comprise user operable controls such as a keyboard, key
pads, buttons,
touch sensitive screen or any other suitable form of user data entry device.
In some cases, the
data entry module 527 may be integrated within the display, for example in
cases where the
display 526 is a touch screen display.
The water analysis device 500 may also comprise a power source 165 for
powering the various
components of the water analysis device 500, including the optical absorption
analyzer 150. This
may be particularly useful in embodiments in which the water analysis device
500 is a
standalone device. In the embodiment depicted in Figure 3, the power source
165 is shown as
comprising a battery 167 (e.g., a lithium-ion battery). In a variant shown in
Figure 17, the power
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source 165 of the water analysis device 500 may comprise a solar panel 600 for
recharging the
battery 167. More specifically, in accordance with a specific example of
implementation, the
solar panel 600 may be disposed on part of the upper portion 514 of the
housing 500 to receive
sunlight which may be converted into an electrical input for the battery 167
of the power source
165. It is to be appreciated that while examples of power sources 165 for the
water analysis
device 500 have been described, many other suitable ways for providing power
to the water
analysis device 500 may be contemplated, including for example through a
connection to
standard wiring, directly or through the bathing unit controller 122 (shown in
Figure 1).
"In-line" configuration of water analysis device 500
In a second type of configuration, shown in Figures 4, 6, 7, 8 and 9, the
water analysis device
500 may be integrated within a circulation system 106 of the bathing unit
system 100 along with
one or more other components of the bathing unit 100, as shown for example in
Figure 6. More
specifically, in such second type of configuration, the housing 502 of the
water analysis device
500 may include a chamber forming a space 504 for holding a sample of water,
wherein the
chamber is in fluid communication with circulation piping 164 of the
circulation system 106 of
the bathing unit 100 such that water from the receptacle 102 is circulated
through the space 504,
notably via an inlet 900 of the water analysis device 500 through which water
enters the space
504 and an outlet 902 of the water analysis device 500 through which water
exits the space 504,
as shown in Figure 18. The chamber may be generally tubular in shape and
includes walls 508
510 having opposing windows 516 518 made of a material permeable to
ultraviolet light such as,
for example, quartz, suitable types of optical glass or any other suitable
material.
Now that we have described some examples of physical configurations of the
water analysis
device 500, we will now describe some different manners in which this device
operates to
monitor halogen levels in water. include some different configurations of the
optical absorption
analyzer 150. It is to be appreciated that the while various examples of the
optical absorption
analyzer 150 may be described with reference to either the standalone
configuration or the in-line
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configuration of the water analysis device 500, these examples may be used
interchangeably with
one or the other configurations in alternative implementations.
Optical absorption analyzer
As mentioned above, the optical absorption analyzer 150 of the water analysis
device 500 is
configured to monitor a concentration of one or more specific halogens (H) in
the water of the
bathing unit 100.
In the embodiment shown in Figures 3 and 4, the optical absorption analyzer
150 comprises a
(first) light source 152 configured to emit a beam of light 154 and a detector
156. In use, the
beam of light 154 emitted by the light source 152 is directed towards a sample
of water 158
obtained from water in the bathing unit 100. Specifically, the beam of light
154 travels through
the window 516 of the housing 502, through the sample of water 158 contained
in the space 504
defined by the housing 502 and through the window 518 of the housing 502. The
detector 156 is
positioned to receive the beam of light 154 after it has travelled through the
sample of water 158
in order to make a measurement of light received from the light source 152. As
will be discussed
in more detail below, by using a light source 152 emitting light at a selected
specific wavelength
that is chosen based on a specific halogen H that is of interest, an estimate
of the concentration of
the halogen H in the water of the bathing unit 100 can be derived from the
measurement made by
the detector 156.
The light source 152 may comprise any of a variety of types of light-emitting
members. In this
specific example of implementation, the light source 152 comprises a light-
emitting diode
(LED). However, the light source 152 may comprise any other type of light-
emitting member in
other examples, such as an incandescent bulb, a discharge lamp, a laser, or
any other suitable
type of light-emitting member. As most light-emitting members emit light in a
diverging manner
(i.e., light rays emitted by the light-emitting member may diverge from one
another), the light
source 152 may also comprise one or more optical elements (not shown) such as
lenses or
concave mirrors which are configured to collimate the light rays emitted by
the light-emitting
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member to direct the light rays towards the sample of water 158. In this
example, where the
light-emitting member is an LED, the optical element of the light source 152
may constitute a
plastic body encapsulating the LED and which is domed to collimate the light
rays emitted by the
LED.
As noted above, the type of light-emitting member comprised by the light
source 152 (e.g.,
incandescent bulb. laser, LED, etc.) may be chosen in accordance with the
specific halogen H
that is to be monitored by the optical absorption analyzer 150. More
specifically, the light-
emitting member of the light source 152 is chosen such that a wavelength of
the beam of light
154 emitted by the light source 152 is absorbed by the specific halogen H that
is of interest. In
this example, where the halogen H being monitored is bromine, the wavelength
at which the
light source 152 emits light would be in the ultraviolet part of the spectrum
between 280nm and
380nm. In some examples, the wavelength at which the light source 152 emits
light may be
between 300nm and 360nm. In a non-limiting practical implementation, the
wavelength at which
the light source 152 emits light is about 310nm. For some non-limiting example
of
implementations, light source 152 may be implemented by using an off-the-shelf
device such as
UV LED device model No. UVLED-UV310R50 commercialized by BYTECH Electronics
Co.,
Ltd. however other suitable types of commercially available light sources may
be used in other
alternative implementations. In accordance with another non-limiting practical
implementation,
the wavelength at which the light source 152 emits light may be about 330 nm.
The detector 156 is a photodetector configured to sense light. To that end,
the detector 156
comprises a light-sensing surface 157 that substantially faces the light
source 152 to receive the
beam of light 154 emitted by the light source 152. More particularly, the
light-sensing surface
157 of the detector 156 converts light photons into current. For instance, in
this example, the
detector 156 is a photoelectric sensor such as a photodiode. The detector 156
may be any other
suitable type of sensor capable of sensing light in other embodiments (e.g., a
phototransistor).
For some non-limiting example of implementations, detector 156 may be
implemented by using
by using an off-the-shelf device such as 4.8mm Semi-Lens Silicon PIN
photodiode model No.
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PD438C/S46 commercialized by Everlight however other suitable types of
commercially
available photodiodes may be used in other alternative implementations.
The optical absorption analyzer 150 also comprises a processing unit 162
configured to process
data related to operation of the optical absorption analyzer 150. For
instance, the processing unit
162 is configured to process a signal transmitted to the processing unit 162
by the detector 156.
Notably, the signal received by the processing unit 162 from the detector 156
is representative of
the measurement of ultraviolet light sensed by the detector 156. In a manner
that will be
explained in more detail below, the processing unit 162 is programmed for
deriving an estimate
of the concentration of the halogen H present in the sample of water 158 based
at least in part by
processing the measurement of ultraviolet light sensed by the detector 156.
The concentration of the halogen H may be derived by Equation 1 (also known as
the Beer-
Lambert equation) reproduced below:
log ()= Ed l (Equation 1)
(pe
In Equation 1 above, (19. is a radiant flux incident on the sample of water
158 and (pet is a radiant
flux transmitted through the sample of water 158. The molar attenuation
coefficient r is a
property of the halogen H while C is a molar concentration of the halogen H in
the sample of
water 158 under study. Finally I is the optical pathlength of the beam of
light 154 (i.e., a distance
the beam of light 154 travels from the light source 152 to the detector 156 in
the sample of water
158). Thus, using Equation 1, the processing unit 162 can derive the molar
concentration C of a
specific halogen H in the sample of water 158.
It is noted that the optical pathlength 1 of the beam of light 154 is
determined by the distance Dw
between the windows 516, 518. Notably, the optical pathlength / of the beam of
light 154 can be
optimized by adjusting the distance Dw. For instance, if the distance Dw
between the windows
516. 518 is made too small, the sample of water 158 may be too small to
contain an appreciable
concentration of the halogen H. Moreover, if the distance Dw between the
windows 516, 518 is
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made too great, the sample of water 158 may contain too many impurities (e.g.,
dirt, air bubbles,
etc.) which may affect the accuracy of the derived concentration of halogen H.
Optionally, in some embodiments, as shown in Figure 3, the optical absorption
analyzer 150 may
be configured to gather water temperature information relating to the water of
the bathing unit
100. To that end, in this example of implementation, the optical absorption
analyzer 150
comprises a temperature probe 180 for sensing the temperature of the water of
the bathing unit
100. More specifically, in such embodiments, the temperature probe 180 makes a
measurement
of the temperature of the water and releases a signal conveying the recorded
water temperature
information to the processing unit 162. This may allow the processing unit 162
to use the water
temperature information when deriving the concentration of the halogen H to
compensate for
effects that may be attributable to variations in water temperature rather
than those that may be
attributable to actual concentration of the halogen H.
Furthermore, optionally, in some embodiments, the optical absorption analyzer
150 may be
configured to gather water acidity/basicity information related to the water
of the bathing unit
100. To that end, the optical absorption analyzer 150 may comprise a pH (PH)
probe 182 for
sensing the water acidity/basicity level of the water of the bathing unit 100.
More specifically, in
such embodiments, the PH probe 182 makes a measurement of the acidity/basicity
level of the
water and releases a signal conveying the recorded water acidity/basicity
information to the
processing unit 162. This may allow the processing unit 162 to use the water
acidity/basicity
information when deriving the concentration of the halogen H to compensate for
effects that may
be attributable to variations in water acidity/basicity rather than those that
may be attributable to
actual concentration of the halogen H.
Once the processing unit 162 has derived an estimate of the concentration c of
the halogen H in
the sample of water 158, the optical absorption analyzer 150 releases a signal
Sc conveying the
derived estimate of the concentration of the halogen H present in the sample
of water 158. The
signal S, released by the optical absorption analyzer 150 can be transmitted
to one or more
entities and used in various ways.
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In some embodiments, as shown in Figure 5A, the signal S, released by the
optical absorption
analyzer 150 may be transmitted to a device 532 remote from the water analysis
device 500 via a
communication link 125 (e.g., a wired or wireless communication link). For
instance, as shown
.. in Figure 3, the water analysis device 500 may optionally comprise an
antenna 535 and suitable
hardware/software modules for transmitting the signal S, to a remote device
532. The remote
device 532 may include a display module and may be configured to display
information
conveying results obtained by the optical absorption analyzer 150. Notably,
the remote device
532 may comprise a processing unit (not shown) and a display 534 for
displaying information
.. derived from the derived concentration of the specific halogen H. The
remote device 532 may be
embodied in any device suitable for a user to interact with. For instance, the
remote device 532
may be a personal computing device or the bathing unit controller 122 of the
bathing unit 100 (as
shown in Figures 1 and 5B). The remote device 532 may alternatively be any
other suitable type
of device in other examples (e.g., desktop computer, a laptop, a tablet, a
smart watch, a personal
.. digital assistant (PDA), or any other suitable computing device etc.).
In some implementations, for example of the type shown in Figure 5B, the
signal Sc released by
the optical absorption analyzer 150 may be transmitted to the controller 122
of the bathing unit
100. In practical implementations, the communication link 125 between the
optical absorption
analyzer 150 and the controller 122 may be wire-line or wireless. In such a
configuration, the
controller 122 may be programmed to cause an action to be performed in
dependence of the
derived concentration of the halogen H. More specifically, in this example,
the controller 122
may compare the derived concentration of the halogen H with a recommended
range of
concentration of the halogen H to determine if an action is to be taken. For
instance, the
controller 122 may comprise a memory (not shown) in which is stored
recommended ranges of
concentrations of respective halogens. This may be implemented as a lookup
table 155 stored in
the memory of the controller 122, an example of which is shown in Figure 16.
For example, the
lookup table 155 may include recommended upper and lower limits of the
concentration of the
specific halogen H (e.g., HI, H2, H3) such as a lower limit of 3ppm and an
upper limit of 5ppm
for bromine. The controller 122 may thus access the data stored in its memory
and compare the
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derived concentration of the halogen H with the recommended range of
concentration of the
halogen H stored in its memory. Based on the comparison, the controller 122
determines if the
derived concentration of the halogen H is greater, less than, or within the
recommended range of
concentration of the halogen H. The controller 122 may be programmed to
implement an action
at least partly dependent on its determination of where the derived
concentration of the halogen
11 falls relative to the recommended range of concentration of the halogen H.
For instance, the controller 122 may derive control signals for conveying
messages to the user of
the bathing unit 100 in order to allow the user adjust the concentration of
the halogen H in the
water of the bathing unit 100. For example, if the controller 122 determines
that the derived
concentration of the halogen H is lower than the recommended range of
concentration of the
halogen H, the controller 122 may convey a message instructing the user to
take steps to increase
the halogen H in the water of the bathing unit 100. If the controller 122
determines that the
derived concentration of the halogen H is greater than the recommended range
of concentration
of the halogen H, the controller 122 may convey a message instructing the user
to limit (e.g.,
stop) adding halogen H to the water, or in some cases, to add water to the
bathing unit 100.
In addition, or alternatively, the controller 122 may derive control signals
for controlling
operation of one or more devices of the bathing unit 100 in order to adjust
the concentration of
the halogen H in the water of the bathing unit 100. For example, if the
controller 122 determines
that the derived concentration of the halogen H is lower than the recommended
range of
concentration of the halogen 11, the controller 122 may derive a control
signal to cause an
electrolytic cell 132 of the sanitizing system 130 to increase an input of the
halogen H into the
water of the bathing unit 100. If the controller 122 determines that the
derived concentration of
the halogen H is greater than the recommended range of concentration of the
halogen H. the
controller 122 may derive a control signal to cause the electrolytic cell 135
of the sanitizing
system 130 to decrease an input of the halogen H into the water of the bathing
unit 100 (e.g., to
stop or reduce the generation of halogen H by a sanitizing device). This may
allow the halogen H
to evaporate from the water and thus reduce the concentration of the halogen
H. Alternatively or
additionally, the controller 122 may derive a control signal configured to
control one or more
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valves (not shown) of the bathing unit 100 to add water into the circulation
system 106 of the
bathing unit 100 such as to reduce the concentration of the halogen H. For
example, in such
cases, the bathing unit 100 may also comprise a water outlet (e.g., a drain)
through which water
from the bathing unit 100 may be expelled and new water (i.e., water free of
the halogen H) may
be added via opening of the one or more valves, thus allowing a reduction of
the concentration of
the halogen H in the water of the bathing unit 100. The controller 122 may
also store the derived
concentration of the halogen H in its memory in a log of derived
concentrations of the halogen H
for future reference. In the event that the controller 122 determines that the
derived concentration
of the halogen H is within the recommended range of concentration of the
halogen H, the
controller 122 may store the derived concentration of the halogen H in its
memory and not take
any action to modify the concentration of the halogen H in the water of the
bathing unit 100.
The transmittal of the signal S, to the controller 122 to cause an adjustment
of an input of the
halogen H into the water of the bathing unit 100 and/or to cause an adjustment
of an input of
water into the bathing unit 100 may thus create a closed loop feedback system
where the
concentration of the halogen H is continuously derived by the processing unit
162 of the optical
absorption analyzer 150 and then adjusted in consequence with the derived
concentration of the
halogen II.
Figure 6 shows a block diagram of a water flow path in which the water
analysis device 500 is
in-line with the circulation system 106 of the bathing unit 100 (as shown in
Figure 4). As shown,
the water of the bathing unit 100 is monitored by the water analysis device
500 to monitor the
concentration of the halogen H in the water, after which the water flows
onwards in the
circulation system 106 to be effected by the sanitizing system 130 on the
basis of the
concentration of the halogen H determined by the water analysis device 500
which, as discussed
above, may increase or decrease the input of halogen H into the water based on
the derived
concentration of the halogen H. From there, the water flows into the
receptacle 102 where the
water is exposed to an environment of the receptacle 102 such that impurities
may or may not be
introduced into the water. The water then flows through the filter 124 where
some impurities
contained in the water may be removed, and then through the pump 112 where the
water is
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pumped to circulate through the circulation system 106. The water then returns
to the water
analysis device 500 where the concentration of the halogen H in the water is
monitored and the
process restarts.
Alternatively or additionally, as shown in Figure 5C, the signal S, released
by the optical
absorption analyzer 150 may be transmitted to the user interface device 524 of
the deice 150 with
which the processing unit 162 is in electronic communication via a connection
127 (e.g., a wired
or wireless connection). The user interface device 524 is configured to
display information
derived from the derived concentration of the halogen H. For example, the
display 526 of the
user interface device 524 displays a plurality of information elements 528,
530 derived from the
derived concentration of the halogen H. For instance, in this example of
implementation, a first
information element 528 may consist of the derived concentration of the
halogen H (e.g., "3.5
ppm") and a second information element 530 may consist of a status of the
concentration of the
halogen H relative to the recommended range of concentrations of the halogen
H. The status of
.. the concentration of the halogen H may be conveyed to the user in various
ways. For example, in
some cases, the second information element 530 may be a color (e.g., red,
yellow, green, etc.), a
symbol (e.g., an exclamation mark), a word (e.g., "LOW", "OK", "HIGH"), or any
other suitable
graphical element to convey to the user whether the derived concentration is
below, within or
above the recommend range of concentrations of the halogen. The information
elements 528,
.. 530 displayed by the display 526 are determined by the processing unit 162
at least in part on the
basis of the derived concentration of the halogen H. For example, the
processing unit 162 may
store a lookup table similar to the lookup table 155 in its memory (not shown)
in order to
determine whether the derived concentration is outside of or within the
recommended range of
concentration of the halogen H and the processing unit determines the
information elements 528,
.. 530 to be displayed on that basis (e.g., red if the concentration of the
halogen H is too low).
In some non-limiting implementations, the signal Sc released by the processing
unit 162 may be
transmitted exclusively to the user interface device 524. That is, the signal
S, released by the
processing unit 162 may be transmitted exclusively locally to the water
analysis device 500 such
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that the signal S, is not transmitted to the controller 122 of the bathing
unit 100 or any other
remote device 532.
Alternatively, as shown in Figure 14, the water analysis device 500 may be
part of a
communication network 550 in which the water analysis device 500 can
communicate with one
or more other devices connected to the communication network 550. The
communication
network 550 may be a wired or wireless communication network. In the example
depicted in
Figure 14, the communication network 550 is a (home) Wi-Fi network established
by a router
552. More specifically, in this example of implementation, the water analysis
device 500
communicates with a plurality of remote devices 532, including for example a
smart phone and a
laptop via respective wireless links 554, 556 established through the Wi-Fi
network.
Alternatively still, the water analysis device 500 may communicate over a
communication link
(wireline or wireless) established directly one or more other devices, without
the need for a WiFi
network.
While embodiments of the optical absorption analyzer 150 have been described
above, it will be
appreciated that the configurations shown can be modified to account for
additional factors and
improve precision when deriving the concentration of the halogen H and/or to
improve or
otherwise facilitate deriving the concentration of the halogen H.
Some variants of the optical absorption analyzer 150 will now be described.
Reference measurement of light emitted by the light source
In a first variant, the optical absorption analyzer 150 may be configured to
make a measurement
of the beam of light 154 emitted by the light source 152 before the light has
travelled through the
sample of water 158. This additional measurement serves as a "reference"
measurement to allow
the determination of the concentration of the halogen H to allow the
processing unit 162
compensate for effects that may be attributable to variations in the
ultraviolet light emitted by the
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light source 152 and/or received by the detector 156 rather than those that
may be attributable to
actual concentration of the halogen H. For example, such variations of the
ultraviolet light
emitted by the light source 152 and/or received by the detector 156 may be due
to variations in
the manufacturing of the light source 152, or the power source 165 and/or
variations that occur
over time as the light source 152 and/or the power source 165 age.
For instance. Figure 7 shows a specific example of implementation in which an
optical
absorption analyzer 150' is configured substantially similarly to the optical
absorption analyzer
150 depicted in Figures 3 and 4, with the exception that the optical
absorption analyzer 150'
comprises a second detector 202 in addition to the (first) detector 156. In
this case, the second
detector 202 is configured to make a reference measurement of the ultraviolet
light emitted by
the (first) light source 152 and may thus also be referred to as a "reference"
detector 202.
More specifically, in use, the first detector 156 records a first measurement
of ultraviolet light
received from the light source 152 after the beam of light 154 has travelled
through the sample of
water 158 and the second detector 202 records a second measurement of
ultraviolet light
received from the light source 152 prior to the beam of light 154 having
travelled through the
sample of water 158. In other words, the second detector 202 receives the beam
of light 154 in an
"unmodified" state (i.e., without the beam of light 154 having travelled
through the sample of
water 158 and interacted with its chemical constituents). To that end, the
second detector 202 is
positioned on a same side of the sample of water 158 as the light source 152
such that the beam
of light 154 does not traverse the sample of water 158 to reach the second
detector 202. More
particularly, in this embodiment, the second detector 202 is positioned such
that its light-sensing
surface 203 faces a direction transversal to the beam of light 154. In other
words, the light-
sensing surface 203 of the second detector 202 faces a direction transversal
(e.g., generally
perpendicular) to a direction faced by the light-sensing surface 157 of the
first detector 156.
Moreover, in this embodiment, the optical absorption analyzer 150' comprises a
beam splitter
module 200 for directing a first portion 170 of the beam of light 154 toward
the first detector 156
and a second portion 172 of the beam of light 154 toward the second detector
202. In other
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words, the beam splitter module 200 directs a first part of ultraviolet light
generated by the light
source 152 toward the first detector 156 and a second part of ultraviolet
light generated by the
light source 152 toward the second detector 202. In this example, the first
and second portions
170, 172 of the beam of light 154 respectively directed to the first and
second detectors 156, 202
are substantially equal to one another (i.e., the amount of light directed to
the first and second
detectors 156, 202 is similar). However, in other examples, the beam splitter
module 200 may be
configured to split the beam of light 154 such that a given one of the first
and second portions
170, 172 of the beam of light 154 is greater than the other one of the first
and second portions
170, 172 of the beam of light 154. For example, in some cases, the first
portion 170 of the beam
of light 154 that is directed to the first detector 156 may be greater than
the second portion 172
of the beam of light 154 that is directed to the second detector 202. This may
be helpful to ensure
that an adequate amount of light reaches the first detector 156 which may be
further from the
light source 152 than the second detector 202.
In some specific practical implementations, the beam splitter module 200 may
comprise a semi-
transparent body to allow the first portion 170 of the beam of light 154 to be
transmitted through
to the first detector 156 and the second portion 172 of the beam of light 154
to be reflected to the
second detector 202.
In other embodiments, as shown in Figure 8, rather than the beam of light 154
being directed to
the second detector 202 by a beam splitter module 200, the second detector 202
may be
configured to receive light directly from the light source 152. For instance,
the second detector
202 may be positioned to receive a portion 175 of the light emitted by the
light source 152 that is
outside of a cone of light collimated and directed to the sample of water 158.
To that end, in such
embodiments, the second detector 202 is positioned such that its light-sensing
surface 203 faces
the light source 152. For example, the light-sensing surface 203 of the second
detector 202 may
face the same direction as the light-sensing surface 157 of the first detector
156.
With the configurations of the optical absorption analyzer 150' described
above with reference to
Figure 7 and 8, the processing unit 162 can derive an estimate of the
concentration of the halogen
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H at least in part by processing results of the first and second measurements
effected by the first
and second detectors 156, 202 respectively. More specifically, based on the
reference
measurement of the light source 162 effected at the second detector 202, the
processing unit 162
can calculate calibration coefficients that account for the variations in the
power of the light
source 152 and which may thus improve accuracy of the derived concentration of
the halogen H.
More specifically, the radiant flux (pe' incident on the sample of water 158
can be measured using
the signal sti, recorded by the second detector 202 while the transmitted
radiant flux (pet (i.e., the
radiant flux received at the first detector 156) can be measured using the
signal .5,'': recorded by
the first detector 156. The first and second detector chains have their own
specific response
functions RR and RA. such that the recorded signals S,i, .5)1' are given by
Equations 2 and 3
reproduced below:
st, = R, 9 (Equation 2)
V = RA(Pet (Equation 3)
Replacing Equations 2 and 3 into Equation 1 results in Equation 4 reproduced
below:
( .5 f,
log L''I')= Ed l (Equation 4)
sl
RA
Similar to what was described above, the optical absorption analyzer 150'
derives an estimate of
the concentration c of the halogen H. To do so, Equation 4 can be transformed
into Equations 5
and 6, shown below, where a and f3 are calibration coefficients:
/ 42 )
c = ¨Ilog ¨
RR (Equation 5)
et SA
\ RA
c = alog (fl 151-1A) (Equation 6)
$A
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The calibration coefficient /3 is defined as a ratio of the first detector
chain response RA over the
reference detector chain response RR as given by Equation 7 shown below:
13 = p (Equation 7)
The calibration coefficient )6 can be measured by using a sample of water
containing no target
halogen (i.e., the concentration c of the halogen H=0) in which case Equation
6 transforms into
Equation 8 shown below:
0 = tog (fl (Equation 8)
Equation 8 can be solved to obtain Equations 9 and 10 shown below:
= p ti (Equation 9)
SA
= (Equation 10)
Using Equation 10, the calibration coefficient [3 can be calculated as a ratio
of the detector signal
over the detector signal SP, , when the concentration c of the halogen H is
null (in other words
no halogen in the water). Meanwhile, the calibration coefficient a in Equation
6 can be
calculated by using an etalon sample (i.e., a sample having standard known
properties) with a
known concentration c of the halogen H (c = c0, as measured by other methods,
such as for
example using a Bromine titration test kit). As such, Equation 6 can be
transformed into
Equation 11 as shown below:
a = co (Equation 11)
log(p)
In other words, Equation 11 can be used to calculate the calibration
coefficient a using the
calibration coefficient p. and the detector signals V, .5,!: measured with the
etalon sample.
Using multiple light sources of different wavelengths
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In another variant, the optical absorption analyzer may be configured to make
a measurement of
light emitted at a wavelength that the halogen H does not substantially absorb
in addition to the
measurement made to gauge the light emitted by the light source 152 whose
wavelength the
.. halogen H substantially absorbs. This may allow the determination of the
concentration of the
halogen H to compensate for effects that may be attributable to impurities in
an optical path
between the light source 152 and the first detector 156 rather than those that
may be attributable
to actual concentration of the halogen H in the sample of water 158. For
example, such
impurities may be due to sand particles in the sample of water 158 and/or
particles having
adhered to the windows 516, 518 between the light source I 52 and the first
detector 156.
For instance, Figure 9 shows a specific example of implementation in which an
optical
absorption analyzer 150" is configured substantially similarly to the optical
absorption analyzer
150' depicted in Figure 7, with the exception that the optical absorption
analyzer 150"comprises
a second light source 204 in addition to the (first) light source 152. The
second light source 204
emits a beam of light 174 that is received by the first detector 156 for
measurement of the light
emitted by the second light source 204. The beam of light 174 emitted by the
second light source
204 has a wavelength that is different from the wavelength of the beam of
light 154 emitted by
the first light source 152. Specifically, the wavelength of the beam of light
174 emitted by the
second light source 204 is such that the beam of light 174 is substantially
not absorbed by the
halogen H. That is, the wavelength of the beam of light 174 is generally
unaffected by the
concentration of the halogen H in the sample of water 158. As the second light
source 204 is
used as a reference, the second light source may be referred to as a
"reference" light source. In
this embodiment, the wavelength of the beam of light 1 74 may emit light in
the visible or near-
.. infrared range of the spectrum (e.g., about 400nm to 1100nm) rather than in
the ultraviolet range.
For instance, in some cases, the wavelength of the beam of light 174 may be
between about
450nm and 600nm, in some cases between about 475nm and 550nm, and in some
cases about
500nm.
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In this example of implementation, the first detector 156 records a first
measurement of
ultraviolet light received from the first light source 152 and the second
detector 202 records a
second measurement of ultraviolet light received from the first light source
152 prior to the beam
of light 154 having travelled through the sample of water 158. The first
detector 156 then records
a first measurement of light received from the second light source 204 and the
second detector
202 records a second measurement of light received from the second light
source 204 prior to the
beam of light 174 having travelled through the sample of water 158 (i.e.,
without the beam of
light 174 having traversed the sample of water 158 and interacted with its
chemical constituents).
As such, in this example, the same first detector 156 is used for making the
first measurements of
.. transmission of light from the first and second light sources 152, 204, and
the same second
detector 202 is used for making the second measurements of transmission of
light from the first
and second Wit sources 152, 204 prior to the light of the respective light
sources travelling
through the sample of water 158.
In this example of implementation, the first and second light sources 152, 204
are sequentially
turned "ON" and "OFF" to allow the detectors 202 and 156 to make their
respective
measurements. More specifically, the first light source 152 is turned "ON"
(i.e., to emit light) for
a period of time and then turned "OFF" (i.e., to cease emitting light) to
allow the second light
source 204 to be turned "ON" for a period of time and then turned "OFF". With
this cycled
approach the optical absorption analyzer 150" can be referred to as a
sequential two-wavelength
analyzer. In order to derive an estimate of the concentration of the halogen,
the processing unit in
Figure 9 may make use of Equations 1 to 11, which also apply to the second
light source 204
albeit with a new molar attenuation coefficient E and new calibration
coefficients a and 1, all
three variables being selected for the wavelength of the second light source
204.
The second light source 204 is positioned on the same side of the sample of
water 158 as the
light source 152 such that the beam of light 174 has to traverse the sample of
water 158 to reach
the second detector 202. More particularly, in this embodiment, the second
light source 204 is
positioned such to face a direction transversal (e.g., generally
perpendicular) to a direction faced
by the first light source 1 52.
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Thus, in order to direct the beam of light 174 emitted by the second light
source 204 to the first
detector 156, the beam splitter module 200, in addition to being configured to
split the beam of
light 154 emitted by the first light source 152, is configured to split the
beam of light 174 emitted
by the second light source 204. Notably, the beam splitter module 200 directs
a first portion 176
of the beam of light 174 towards the first detector 156 and a second portion
178 of the beam of
light 174 towards the second detector 202. In this example, the first and
second portions 176, 178
of the beam of light 1 74 respectively directed to the first and second
detectors 156, 202 are
substantially equal to one another (i.e., the amount of light directed to the
first and second
detectors 156, 202 is similar). However, in other examples, the beam splitter
module 200 may be
configured to split the beam of light 174 such that a given one of the first
and second portions
176, 178 of the beam of light 154 is greater than the other one of the first
and second portions
176, 178 of the beam of light 154. For example, in some cases, the first
portion 176 of the beam
of light 174 that is directed to the first detector 156 may be greater than
the second portion 178
of the beam of light 154 that is directed to the second detector 202.
With the configuration of the optical absorption analyzer 150" described
above, the processing
unit 162 can derive the concentration of the halogen H at least in part by
processing results of the
first and second measurements of transmission of light from the first light
source 152 and the
first and second measurements of transmission of light from the second light
source 204. More
specifically, based on the measurements of the light received from the second
light source 204,
the processing unit 162 can calculate a calibration coefficient that accounts
for the impurities and
whose inclusion in calculating the concentration of the halogen H may thus
improve an accuracy
of the derived concentration of the halogen H. This calibration coefficient
may thus be referred
to as an "interference coefficient" in some cases.
Notably, according to the principles of optical absorption, when two chemical
species (labeled 1
and 2) are present in the sample of water 158, the Beer¨Lambert equation
becomes Equation 12
for the first light source 152 and Equation 13 for the second light source
204, as shown below:
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log 4s = dc10_ + 41c21`2 (Equation 12)
log = ci1 + 4c21 (Equation 13)
Equation 14, reproduced below, is obtained by subtracting Equation 13 from
Equation 12:
/SO
-Ft
log 4 ¨ log 14- = EPcili + dc212 ¨ + dc2l2) (Equation 14
sA
\RA/ RA
If the first light source 152 and the second light source 204 are collinear,
the optical pathlengths
for their beams can be considered to be equal, as expressed in Equations 15
and 16 below:
1 = l = 1, (Equation 15)
= l = 12 (Equation 16)
The optical pathlength /, (for the first light source 152) is kept distinct
from the optical
pathlength /2 (for the second light source 204) to cover cases for example
where the chemical
species 2 is deposited on the windows 516, 518 as a thin layer and chemical
species 1 is present
throughout the volume of the sample of water 158. By combining Equations 14,
15 and 16.
Equations 17 and 18 are obtained as shown below:
sFit
log 4 = ¨ + c212(d ¨ Ef) (Equation 17)
sA cR
RA
log (sIssARR) = c111f1 + c2l2-2 (Equation 18)
In Equations 17 and 18. and 4-, are the effective molar attenuation
coefficients as defined in
Equations 19 and 20 shown below:
¨ E (Equation 19)
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= 4 - ET (Equation 20)
The second light source 204 can be chosen to emit wavelengths so that the
molar attenuation
coefficient of the second interfering chemical species is substantially the
same as for the first
light source 152.
. A granular opaque inhomogeneous contaminant such as dirt can cause this type
of progressive
decrease of transmission affecting wavelengths of light emitted by the first
and second light
sources 152, 204 in a similar manner. One can also find a wavelength for the
second light source
204 so that a film of matter reduces the light intensity in a manner similar
to the wavelength of
the light beam 154 emitted by the first light source 152. When this happens, 2
= 0, as can be
seen in Equation 21 below:
= 4 - 12? = 0 (Equation 21)
To illustrate the above, let us say that we have an interfering species in the
optical path between
the first light source 153 and the detector 156. If this species is
interfering, it means that it
absorbs at the wavelength at which the first light source 152 is emitting
light, the same
wavelength used to measure the concentration of the specific halogen H. If
only one wavelength
is used, the presence of this interfering species in the optical path will
reduce the intensity of the
wavelength received at the detector 156 and the optical absorption analyzer
will "think" that a
greater concentration of halogen H is present in the water.
By choosing the wavelength of the second light source 204 so the interfering
species absorbs the
same amount at the wavelength of the second light source 204 and at wavelength
of the first light
source 152, a simplification occurs as can be seen by equations 19 and 20
above and the
information provided by the second light source 204 allows us to compensate
for this interfering
absorption in order to derive an estimate of the concentration of halogen H
where the effects of
the interfering species have been compensated..
One example is dirt accumulating on the window. Assume that each grain of dirt
is 100%
absorbing at all wavelengths (opaque). The transmittance of the window will be
given only by
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the percentage of surface covered by this opaque material. Another example
would be a material
that attenuates all wavelengths by the same ratio, a neutral absorber. In both
of these examples
Equation 21 holds.
A specific non-limiting way to achieve the condition in equation 21 is to
choose the wavelength
of the second light source 204 to be as close as possible to the wavelength of
the first light source
152, while being away from the maximum absorption wavelength of the halogen H.
Equation 22, reproduced below, can be obtained by replacing Equation 21 in
Equation 18:
/ \
Cl = n/0901
sAso (Equation 22)
Equation 22 contains a calibration coefficient yi that can be calculated using
an etalon sample
with a known concentration of the halogen H ( = c0), as measured by another
method. In this
case, the calibration coefficient yi (which we can also refer to as the
interference coefficient) can
be obtained by Equation 23 shown below:
t (Equation 23)
tog(ssi
The "ideal" optical absorption analyzer 150" would be configured such that the
halogen H
absorbs strongly at the wavelengths of the light emitted by the first light
source 152 and not at
all, or in practice significantly less, at the wavelengths of the light
emitted by the second light
source 204. In this -ideal" optical absorption analyzer 150", the second light
source 204 is
chosen so there is negligible absorption by the halogen H at the wavelength of
the light emitted
by the second light source 204. If this is not possible, the optical
absorption analyzer 150" will
still produce a usable result as long as the absorption of light by the
halogen H is sufficiently
different at the wavelength of the light emitted by the first light source 152
and at the wavelength
of the light emitted by the second light source 204.
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Optionally, in some embodiments, the water analysis device 500 may use the
interference-related
information (e.g., the interference coefficient yi) to inform the user of a
cleanliness status of the
water and the windows 516, 518 of the housing 502.
More specifically, in some embodiments, the processing unit 162 of the water
analysis device
500 may be configured to transmit to the user interface device 524 of the
water analysis device
500, and/or the remote device 532 to which the water analysis device 500 is
connected, the
interference-related information gathered from monitoring the sample of water
158. For instance,
in addition to the derived concentration of the halogen H, the signal Sc
transmitted by the
processing unit 162 to the user interface device 524 and/or the remote device
532 may include
the interference-related information. In turn, the user interface device 524
and/or the remote
device 532 may display information derived from the interference-related
information received
in the signal Sc. For instance, in a specific example of implementation, as
shown in Figure 13,
the display 526 of the user interface device 524 may display a third
information element 531
derived from the interference-related information. For example, the third
information element
531 may consist of a cleanliness status of the water and/or of the windows
516, 518 of the
housing 502 which may be expressed graphically or numerically in any suitable
way. In this
example, the cleanliness status is expressed as a rating on a given scale
(e.g., 1/10, 2/10, 3/10,
etc.) to inform the user of the cleanliness of the water of the bathing unit
100 and/or of the
windows 516, 518 of the housing 502. This may be advantageous for the user to
take action, if
necessary, based on the cleanliness status displayed by the user interface
device 524 and/or the
remote device 532. For example, the user may be compelled to clean the windows
516, 518 of
the housing 502 and/or verify the functionality of the filter 124 of the
bathing unit 100.
Using light sources of different wavelengths and operating them at different
frequencies
In some variants, the first and second lights sources 152, 204 of the optical
absorption analyzer
150" depicted in Figure 9 may be continuously left "ON" and may be operated
according to an
intermittent (e.g., periodic) light pattern (e.g., with a variable
modulation), such as for example,
but without being limited to, a sinusoidal light pattern or a square wave
light pattern.
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Advantageously, keeping the first and second light sources 152, 204 "ON" and
operating them
according to an intermittent light pattern may present a number of advantages
including reducing
transition effects caused by activating / deactivating the light sources 152,
204.
In order to achieve this, the first and second light sources 152, 204 may be
operated at different
frequencies. For instance, the first light source 152 emits light at a first
frequency F1 and the
second light source 204 emits light at a second frequency F7 different from
the first frequency F3.
Preferably, the first and second frequencies F1 and Fi are selected so that
they are not harmonics
of one another. In this embodiment, the optical absorption analyzer 150" may
be configured to
.. derive the concentration of the specific halogen H at least in part based
on a frequency
distribution associated with the results of the first and the second
measurements of the
transmission of light from the first light source 152 and the results of the
first and the second
measurements of the transmission of light from the second light source 204.
Advantageously, by
selecting certain first and second frequencies, effects of some external
sources of interference
may be reduced on the measurements of the transmission of light from the first
and second light
sources 152, 204. External sources of interference may include, for example
but without being
limited to, changes in ambient light (for example due to the time of day, the
amount of sun, the
type of light, clouds, etc.) as well as the presence of electrical/electronic
EM fields (typically
caused by the electrical grid ¨ 60Hz, 120Hz and harmonics (240Hz. 480Hz,
etc.)).
In some specific practical applications, the first and second frequencies F1,
F2 may be chosen so
that they are not harmonics of one another and so that they are not harmonic
of signals that are
considered "noise" (e.g. electricaPelectronic signals). In a specific non-
limiting example of
implementation, the first frequency F1 is greater than the second frequency
F2. For instance, the
first frequency F1 may be between 420 and 580Hz, such as for example about
450Hz.
Furthermore, the second frequency F2 may be above 350Hz, such as for example
between 350Hz
and 200kHz, in some cases between 400Hz and 1kHz, in some cases between 500Hz
and 800Hz,
in some cases between 540Hz and 600Hz, such as for example about 570Hz.
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In this embodiment, the signals produced by the light received at the first
and second detectors
156, 202 are composed of a superposition of the signals produced by light
emitted by each of the
first and second light sources 152, 204. The amplitude of the signals recorded
at the first and
second detectors 156, 202 can be derived by applying a Fourier transform
demodulation to
obtain a frequency domain representation of the signals recorded at the first
and second detectors
156, 202. The signals produced by the light of the first and second light
sources 152. 204 have
amplitudes A1, A,) (which may correspond to the signals s:, s: in equation 22
above). Figure 12A
depicts a frequency domain representation of signals received at the first
detector 156, and shows
that the signal recorded at the first detector 156 has peak amplitudes A1',
A?' which are smaller
than the original amplitudes A1, A2 (shown in Figure I 2B) measured at the
second detector 202.
This variation in amplitude may be attributed to an absorption of light by the
halogen H and by
impurities contained in the sample of water 158. The maximum amplitudes A1',
A?' (which may
correspond to the signals v, s: in equation 22 above) forming the peaks of the
signal, or the
area of the peaks may be used. In this example, the greater amplitude A2'
corresponds to the light
received from the second light source 204 at the first detector 156 at the
second frequency F2 and
the smaller amplitude A1' corresponds to the light received from the first
light source 152 at the
first detector 156 at the first frequency F1.
Figure 12B depicts the frequency domain representation of the signals received
at the second
detector 202, and shows that the signal recorded at the second detector 202
has peak amplitudes
A1, A2 which arc approximately equal to one another in this example. Using A1,
A2 AC, A2' in
equation 22, an estimate of the concentration of halogen H in the sample of
water 158 can be
derived.
In specific implementations, the first and second signals are modulated in
order to shift these
signals away from interfering signals. Choosing two distinct frequencies for
the two sources
allows us to operate them simultaneously, removing the need to various timed
sequences (source
152 "ON", source 204 "OFF", etc...). Demodulation (Fourier transform) allows
separating the
signals from interfering influences occurring at other frequencies. In
specific implementation, the
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first and second frequencies of modulation of the light sources may be chosen
at frequencies
where minimal amounts of interference exist.
alternatively, the first and second frequencies of the light sources may be
chosen to be
sufficiently high so that a high pass filter may in some cases be used to
filter out effects of
changes in ambient light, which would typically be at relatively low
frequencies (e.g., such as the
passage of a cloud). In addition, a suitable filter, such as a band-pass
filter, may be used to filter
out effects of the electrical/electronic signals (e.g., by discriminating
against selected frequencies
such as 60Hz, 120Hz and harmonics) without hindering the first and second
frequencies F1, F2 of
the first and second light sources 152, 204. In such cases, the first and
second frequencies F1, F2
of the light sources 152, 204 may be chosen not to correspond to a harmonic of
the
electrical/electronic signals.
Processing unit 162
Figure 10 depicts a functional block diagram of processing unit 162 in
accordance with a specific
embodiment. In this embodiment, the processing unit 162 of the optical
absorption analyzer 150,
150' and 150" comprises a controller 700 configured to receive inputs from and
issue outputs to
other modules of the processing unit 162 and entities outside of the
processing unit 162. For
example, the controller 700 is in communication with a light source driver 702
of the processing
unit 162 that is configured to send a signal to one or more light sources 704
(e.g., first and
second light sources 152, 204) of the optical absorption analyzer 150, 150',
150" to
actuate/deactivate the one or more light sources 704. The processing unit 162
also comprises a
current to voltage converter 710 in communication with one or more detectors
706 (e.g., first and
second detectors 156, 202) and configured to produce a voltage proportional to
a current
received from the signal transmitted to the processing unit 162 by the
detectors 706. The current
to voltage converter 710 is in communication with an analog to digital
converter 712 which
converts the analog signal produced by the current to voltage converter 710
into a digital signal.
The digital signal produced by the analog to digital converter 712 is then
transmitted to a data
processing module 714 of the processing unit 162, where the data contained in
the digital signal
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transmitted to the data processing module 714 is processed. For example, the
data processing
module 714 may be configured to derive an estimate of the concentration of the
halogen H in the
manner described above.
The controller 700 comprises a memory (not shown) for storing data therein.
More specifically,
the memory 165 may store data related to operation of the water analysis
device 500. For
example, this may include operational parameters of the optical absorption
analyzer 150 and/or
reference data related to one or more halogens which can be monitored by the
water analysis
device 500. For example, the lookup table previously discussed, similar to the
lookup table 155
depicted in Figure 16, may be stored in the memory of the controller 700.
Other data related to
operation of the water analysis device 500 may also be stored in the memory of
the controller
700. For example, data related to the wavelength associated with the different
light sources,
frequencies at which the light sources can be operated and other such data is
stored in the
memory of the controller 700.
The controller 700 also receives inputs from and issue outputs to entities
outside of the
processing unit 162. For instance, the controller 700 may be in communication
with a
temperature probe 180 to receive the signal conveying the temperature of the
water. Moreover,
the controller 700 may be in communication with the user interface device 524,
including the
display 526 and the data entry module 527. This may be useful to allow a user
to provide
information related to operation of the water analysis device 500 into the
processing unit 162.
For example, this may include making a selection of the halogen H which is
intended to be
monitored by the water analysis device 500. As another example, this may allow
connecting the
device 500 to the communication network 550 (e.g., entering a password to a Wi-
Fi network).
In embodiments where the water analysis device 500 is part of the
communication network 550,
as depicted in Figure 14, the controller 700 may interface with the
communication network 550
via a communication module 752. The communication module 752 may be for
example a
receiver, transmitter or transceiver that allows the processing unit 162 to
communicate with the
communication network 550.
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89003-189
The embodiments described above are intended to be exemplary only.
It will be apparent to the person skilled in the art in light of the
specification that many variations
are possible. For example, while embodiments of devices described in the
present application
including a processor programmed for deriving the concentration of a specific
halogen by
processing various measurements of light transmission obtained by photo-
detectors of the
apparatus, it is to be appreciated that such computations need not occur in
the device 500 itself
but may in some implementations be implemented by processors located remotely
from the
device 500, including processors that may be located at the bathing unit
controller 122 or in the
cloud. In such cases measurements of light transmission, once obtained by the
photo-detectors,
would be transmitted to the remote location including one or more processor
programmed for
implementing some of the processing functionality, including some of the
computations,
described in the present application.
It will also be understood by those of skill in the art that throughout the
present specification, the
term "a" used before a term encompasses embodiments containing one or more to
what the term
refers. It will also be understood by those of skill in the art that
throughout the present
specification, the term "comprising", which is synonymous with "including,-
"containing," or
"characterized by," is inclusive or open-ended and does not exclude
additional, un-recited
elements or method steps.
Unless otherwise defined, all technical and scientific terms used herein have
the same meaning
as commonly understood by one of ordinary skill in the art to which this
invention pertains. In
the case of conflict, the present document, including definitions will
control.
As used in the present disclosure, the terms "around", "about" or
"approximately" shall generally
mean within the error margin generally accepted in the art. Hence, numerical
quantities given
herein generally include such error margin such that the terms "around",
"about" or
"approximately.' can be inferred if not expressly stated.
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=
89003-189
Althouuh various embodiments of the invention have been described and
illustrated, it will be
apparent to those skilled in the art in light of the present description that
numerous modifications
and variations can be made. The scope of the invention is defined more
particularly in the
appended claims.
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