Note: Descriptions are shown in the official language in which they were submitted.
.~ WO95/31107 PCT~S9510~30
.,,~
METHOD AND CARTRIDGE FOR OBTAINING SOIL SAMPLES
Field of the Invention
This invention relates generally to devices used for
testing and, more particularly, to devices used for soil
testing.
Backqround of the Invention
Soil sampling tools and devices are used for a
variety of purposes, e.g., to obtain samples for soil
moisture content or to sample a volatile organic compound
(VOC) which may have permeated the soil. And soil cores
W095/31707 21 8 9 8 5 ~ PCT~SgS/05830
are removed for other re~so~s unrelated to VOC analysis.
Examples of soil coring and sampling tools are shown in
U.S. Patent Nos. 3,326,049 (Eley); 3,444,938 (Ballman);
3,497,018 (Schultz et al.) and 4,989,678 (Thompson).
The device shown in the Eley patent has a barrel
with air vent and a shaft threaded to the barrel. The
shaft is graduated so that when turned, the soil sample
is ejected in increments. The kit shown in the Thompson
patent includes a sampling device and a sample
containment device, both of which are used for analyzing
a soil sample containing a VOC.
It is common knowledge that tanks for storing
liquids may, over time, develop a leak. If the tank is
above ground, the leak is usually observed rather soon
after its onset and not much damage results. On the
other hand, there is an already-substantial and growing
awareness that certain types of liquid storage tanks
placed unde,yroulld have a greater-than-normal propensity
to deteriorate and leak. Such types include tanks made
of common sheet steel from which protective coatings have
either been eaten away or were non-existent. And a
substantial factor contributing to the risk of tank
leakage is that with an underground tank, leakage is not
visible. Usually, such leakage can only be detected by
excavation and testing.
And the risks are enormous. Undetected leaks of
underground storage tanks can and do contaminate soil and
potable water supplies, the latter by polluting
underground aquifers from which a great deal of drinking
water is drawn. Recent legislation recognizes risks
presented by leaking underground storage tanks and
provides for remediation of damage caused by such leaks.
Because of the number of gasoline service stations and
private fuel and solvent storage tanks, leakage of
petroleum distillates and hydrocarbons is a particularly
significant problem.
WO95/31707 21 89 ~55 PCT~S55/05830
-3
Good remediation requires that personnel be able to
accurately determine the nature and extent of the leak.
Such determination depends in large part upon the
availability of high quality test instruments and the
ability to preserve the integrity of a soil sample (and,
particularly, to prevent evaporation of VOCs therein)
once the sample is taken. The efforts of earlier workers
in this regard have not been entirely satisfactory.
For example, the Thompson patent emphasizes speed of
transfer of a soil sample from a sampling tool to a
containment device to minimize loss of VOC. This is a
less-than-fully-satisfactory solution to retention of
sample integrity, especially if the leaky tank was
installed at a site distant from the analyst's
laboratory. Other known prior art patents show soil
sampling tools having handles which are not easily
removed. And if removable, there is no good way to seal
that end of the barrel from which the handle is removed.
To put it another way, earlier known sampling tools fail
to offer optimum solutions for preserving VOCs in soil-
samples and for reducing the substantial storage space
required to transport what may be dozens of tools to and
from a site.
Obiects of the Invention
It is an object of the invention to provide a soil
sample containment cartridge overcoming some of the
problems and shortcomings of the prior art.
Another object of the invention is to provide a
soil sample containment cartridge which preserves the
integrity of the VOC in a soil sample.
Yet another object of the invention is to provide a
soil sample containment cartridge which avoids sample
contamination.
Another object of the invention is to provide a soil
sample containment cartridge which saves substantial
space when transporting samples from a possibly-
218985~
woss/31707 PCT~S9S/05830
~ --4
contaminated site to a laboratory. How these and other
objects are accomplished will become apparent from the
following descriptions and the drawing.
SummarY of the Invention
Aspects of the invention involve a method for
obt~; n; ng a soil sample using a unique tool-like soil
sample containment cartridge. Such method includes the
steps of providing a generally-cylindrical cartridge
having an open distal end and a proximal end sealed by a
removable plug. A removable handle is attached to the
cartridge and the cartridge then used to "core out" and
extract a soil sample.
Following sample extraction, the "mouth portion" at
the distal end is closed, preferably by applying a cap to
such mouth portion. For optimum sealing, the applying
step includes compressing a resilient seal between the
cap and the mouth portion. And the handle is detached
but end closure and handle detachment may be in either
order. Using such method, the soil sample and any VOC
therewith is quickly "captured" in the cartridge for
preservation, transport and later analysis.
In other aspects of the method, the handle detaching
step is followed by the steps of transporting the
cartridge for analysis and moving the plug along the
cartridge barrel toward its mouth portion to expel the
soil sample from the cartridge. To move the plug, a rod-
like implement is provided for applying force to the
plug. The implement is coupled to the plug and the plug
and soil sample pushed out.
Structural aspects of the invention involve a tool-
like cartridge for preserving a core-like soil sample
after such sample has been removed from a site possibly
contaminated with VQC. The cartridge has a barrel, a
plug in the barrel for expelling a soil sample therefrom
and an attachment portion on the barrel and having an
opening therethrough. The plug has a stud exten~;ng
WO95/31707 21 8 9 8 5 5 PCT~S95/05830
-5
through the opening and a seal between the plug and the
attachment portion prevents VOC from escaping through
such opening. The plug is secured by a nut threaded to
the stud. When so sealed, the cartridge is suitable for
preserving a soil sample containing a volatile organic
compound.
More specifically, the plug has an imperforate face
plate and a sealing member is interposed between the face
plate and the attachment portion for sealing the opening.
Preferably, such member is a resilient seal such as an O-
ring. And if the attachment portion is threaded or
otherwise configured for easy handle attachment and
detachment, there is a cover for protecting such portion.
At its end opposite the attachment portion, the
cartridge has a mouth portion and a cap sealing the mouth
portion. Such cap prevents VoC vapors from escaping from
the mouth end of the cartridge after sample extraction
and before the sample is transported to and analyzed in a
laboratory.
Other aspects of the invention make it easy to expel
the well-preserved soil sample from the cartridge after
such cartridge has been transported to a laboratory.
Quick, easy expulsion of the sample to a containment vial
for analysis is important to preserve any VOC present in
such sample.
In a preferred procedure, one (or, more typically,
several) cartridges are supplied to the user, each having
its plug stud extended through the opening of its
attachment portion and held there by a nut. When the
stud is so positioned, the sealing member is compressed
against the attachment portion and the proximal end of
the cartridge is thereby sealed. A handle is also
supplied.
To collect a possibly-contaminated soil sample, the
handle is attached to the cartridge and the barrel of the
assembled tool forced into the earth and then withdrawn
218~8~5
WO9S/3l707 ~ PCT~S95/05830
with a "core" of soil inside. A cap is promptly placed
on the mouth portion, the handle is removed and the
sample, now completely sealed in the cartridge, is ready
to be transported to a laboratory. If the handle is
attached to the cartridge by threads, it is desirable to
protect the cartridge threads with a cover after removing
the handle but before cartridge transportation.
The stud includes an interior cavity having a
threaded cavity wall. When the lab analyst is ready to
expel the sample from the barrel, the nut is removed and
a rod-like implement is attached to the stud for pushing
the plug toward the mouth portion and expelling the
sample.
Other details of the invention are set forth in the
following detailed description and in the drawing.
Brief Descri~tion of the Drawinq
FIGURE 1 is a perspective view of an embodiment of
the improved tool with parts broken away and other parts
shown in phantom outline.
FIGURE 2 is, generally, a cross-sectional view of
the tool of FIGURE 1 taken along a viewing plane
coincident with the longitudinal tool axis, with parts
broken away and other parts shown in full representation.
FIGURE 3 is a side elevation view, partly in cross-
section, of the tool plunger and ejector.
FIGURE 4 is a cross-sectional side elevation view,
with parts broken away, showing a variation of a portion
of the tool of FIGURE 1.
FIGURE 5 is a side elevation view, with parts broken
away, showing a variation of another portion of the tool
of FIGURE 1.
FIGURE 6 is a representative cross-sectional side
elevation view of a suspected leaky underground storage
tank site which is to be analyzed using bored holes.
WO95/31707 2~ 8~:855 - PcT~sg5los83o
~_ -7
FIGURE 7 is a representative cross-sectional side
elevation view of a site like that of FIGURE 6 which is
being analyzed using a dug hole.
FIGURE 8 illustrates how a soil sample is ejected
into a vial for later sample analysis.
FIGURE 9 is a side elevation view of a variation of
the tool including a biasing spring.
FIGURE 10 is a side elevation view, partly in cross-
section and with parts broken away, of another variation
of the tool including a biasing spring.
FIGURE 11 is a cross-section elevation view of a new
sample-preserving cartridge.
FIGURE 12 is a view of a handle used with the
cartridge of FIGURE 11.
FIGURE 13 is a view of a rod-like implement used to
urge a soil sample from the cartridge of FIGURE 11. Part
is broken away.
Detailed Descri~tions of Preferred Embodiments
The improved soil sampling tool 10 is particularly
useful in collecting soil samples 11 permeated with a
VOC. As described below, the tool 10 has new features
facilitating sample preservation, storage, transportation
and identification. Such features will be welcomed by
those having responsibilities for leak-site analysis and
remediation.
Referring first to FIGURES 1 and 2, the improved
sampling tool 10 includes a hollow, generally cylindrical
barrel 13 having an end wall 15 and a mouth portion 17.
The interior region 19 of the barrel 13 is of generally
uniform diameter along its length and has a volumetric
capacity of 25-30 grams, for example. The edge 21 of the
mouth portion 17 is bevelled inward, resulting in a
- relatively sharp soil-cutting "blade."
An elongate, tube-like handle 23 is concentrically
attached to the barrel end wall 15. In a preferred
embodiment, the handle 23 is separably attached to the
woss/31707 21 8 9 85 S : PCT~S95/05830
end wall 15 (by a threaded connection 25, for example as
shown in FIGURE 4) so that the handle 23 and barrel 13
can be readily attached to and detached from one another
for purposes described below. The T-shaped handle shown
in FIGURES 1 and 2 is preferred in situations where soil
samples 11 are expected to be taken from dense,
relatively hard soils such as clay soils. The T-shaped
handle 23 affords an opportunity to apply a substantial
insertion force to the tool 10.
The handle 23 has a passage 27 extPn~ing along its
length for receiving a rod-like ejector 29 and the handle
23, passage 27 and ejector 29 are preferably circular in
cross-sectional shape. The diameters of the passage 27
and the ejector 29 are cooperatively selected to provide
slight clearance therebetween so that the ejector 29 may
move freely within the passage 27.
As best seen in FIGURE 2, the barrel 13 has an end
aperture 31 and the ejector 29 and aperture 31 define an
air exhaustion clearance 33 between them. Since there is
just enough space between the rim 35 of the plunger 37
and the interior wall 39 of the barrel 13 to permit
relatively free sliding plunger movement, such clearance
33 permits air to escape along the passage 27 as the tool
10 is urged into soil and the plunger 37 is thereby
driven toward the end wall 15.
Referring additionally to FIGURE 3, a disc-like
plunger 37 is mounted to the distal end 41 of the ejector
29 and has a boss 43 exten~;ng a short distance from the
plunger 37. For reasons described below, the ejector 29
and plunger 37 are preferably readily attachable to and
detachable from one other. In the illustrated exemplary
embodiment, the boss 43 has a threaded pocket 45 and the
ejector distal end 41 is similarly threaded for
attachment to the boss 43. At its proximal end 47, the
ejector 29 includes a thumb engagement member 49 so that
when the handle 23 and member 49 are grasped "hypodermic
fashion," the member 49 may be depressed toward the
WO95/31707 2 I 8 9 ~ S 5 pcT~s95los83o
_ g _
handle 23 to eject a soil sample 11 from the barrel 13.
And as shown in FIGURE 5, the thumb engagement member 49
may be ring-like in shape and a handle 23 with side rings
50 may be provided instead of the T-shaped handle 23
shown in FIGURES 1 and 2.
Since such samples 11 are usually transported to a
laboratory for analysis, it is highly preferred that VOC
vapors be prevented from escaping from the sample 11 and
from the tool 10 through the aperture 31. Diminution of
the amount of vapor and VOC present in the sample 11 will
"skew" the test results and may cause the level of soil
contamination to appear less than it actually is.
Accordingly, the plunger boss 43 seals the aperture 31
when the plunger 37 is closely adjacent to or in contact
with the barrel end wall 15. Sealing is by a resilient
O-ring 51 seated in a circumferential groove in the outer
surface of the boss 43.
It is highly preferred that the aperture 31 be
sealed even as the tool barrel 13 starts penetrating into
the soil. In the embodiments described above, the
plunger 37 may be spaced away from the barrel end wall 15
when penetration starts, especially if the tool 10 is
prior held with the barrel 13 downward. Referring to
FIGURES 1 and 9, the plunger 37 is biased by a spring 89a
or 89b to the sample-extracting position, i.e., that
position at which the plunger 37 seals the aperture 31.
In that way, VOC vapors are prevented from escaping
through the aperture, especially at the onset of sample
"cutting."
In the arrangement of FIGURE 1, the compression
spring 89a is interposed between the handle 23 and the
thumb engagement member 49. In the arrangement of FIGURE
9, the tension spring 89b is attached to and extends from
the side rings 50 downward (as viewed in FIGURE 9) along
the handle 23. A coupler rod 91 extends between the
lower end of the spring 89b and a collar 93 immediately
below the member 49. In each instance, the spring 89a,
WO95/3l707 ~ PCT~S95/05830
2 ~ 8 9 8 ' _
--10--
89b biases the ejector 29 and its plunger 37 upward to
seal the aperture 31. The aperture 31 may be sealed by
an O-ring 51 on the plunger boss 43 as described below.
In the arrangement of FIGURE 10, the tool 10
includes a hollow tube 95 received telescope-fashion in
the handle 23. The upper end 97 of the tube 95 is
attached to a thumb engagement member 49 as is the
ejector 29. A compression spring 99 is confined between
the lower end 101 of the tube 95 and the top of the
barrel 13. The spring 99 biases the tube 95, member 49
and ejector 29 upward in the absence of downward force on
the member 49.
Referring further to FIGURES 1 and 2 and to FIGURE
8, it is preferred that the barrel interior region 19 be
completely sealed after a soil sample 11 is taken but
before the sample 11 is ejected to a vial 53 for sample
analysis. To that end, the improved tool 10 also
includes a cup-like cap 55 which has an interior cavity
57 and a cavity wall 59. The cap cavity 57 has a cross-
sectional shape generally conforming to that of thebarrel 13 which, in the preferred embodiment, is
cylindrical. A resilient O-ring 51a is seated in a
circumferential groove 61 formed in the cavity wall 59.
Such O-ring 51a helps assure a vapor-tight seal against
the mouth portion 17 when the cap 55 is placed on such
portion 17.
It should be understood that sealing the barrel
interior region 19 can be accomplished in other ways.
For example, the boss 43 and aperture 31 can be formed to
permit very closely fitted, sliding clearance between
them and thereby provide a relatively good vapor seal.
The barrel outer wall 63 and the cap cavity wall 59 can
be similarly formed. However, use of O-ring seals 51,
51a permits some "forgiveness" in certain manufacturing
dimensional tolerances and should result in a reduced
manufacturing cost.
21~855
woss/31707 PCT~S95/05830
--11--
As explained in the summary, when O-rings 51, 51a
are used for sealing, some difficulty may be experienced
in positioning the sealing "pieces" (the boss 43 or the
cap 55) to a fully seated position if the pieces are not
made to close tolerances. If needed, a seal lubricant 65
may be applied to the rings 51, 51a and nearby surfaces
to help avoid such difficulty. However, care must be
taken to avoid sample contamination by a petroleum-based
product such as a lubricating oil. Therefore, a highly
preferred lubricant 65 is powdered graphite.
The following is an explanation of how and where
soil samples 11 are taken and identified and how such
samples 11 are handled in preparation for lab analysis.
It is assumed that the site 67 of a suspected leaking
underground storage tank has been identified and such
site 67 is shown generally in FIGURES 6 and 7. As shown
in FIGURE 6, those involved in determining whether and to
what extent contamination exists at the site 67 will bore
holes 69 (to avoid sampling at the earth surface where
VOC and vapors may be less concentrated) and use what is
known as a split spoon device 71 (resembling a "plunge
type" post hole digger) to extract relatively large
"slugs" 73 of soil from various holes 69. Using the tool
10, a soil sample is taken from a location 75 (or perhaps
two or more locations) on the slug 73. Each slug 73 is
removed at a known depth and from a hole 69 have a known
location. Both such informational items are recorded for
"mapping" the site 67 with a field sketch.
Referring to FIGURE 7, in another approach, a hole
77 is dug in the earth. Samples are taken at various
horizontally and vertically spaced locations 75 along the
generally vertical wall 79 of the hole 77 and, probably,
at other locations. The wall 79 and the locations 75
will similarly be mapped with a field sketch.
Irrespective of whether bored or dug holes 69, 77
are used, each such sample location 75 is identified on
the sketch with a designator 81 which is unique for that
WO95/31707 ~ ~ g ~'5 S PCT~S95105830
--12-
site 67. It is likely that soil samples 11 will be taken
from several dozen locations 75 at a particular site 67.
For reasons that will become apparent, sampling a site 67
therefore involves having a substantial number of tools
10 available, i.e., at least a quantity equal to the
number of locations 75.
Referring again to FIGURE 1, the designator 81 used
for a particular location 75 is that which is marked on
the tool 10 used to take that particular sample 11. The
designator 81 is preferably prominently marked on the
tool 10, e.g., on the barrel. Since a particular tool 10
will be used many times (at different sites 67) and since
such tools lO must be thoroughly washed and cleaned prior
to use, marking is preferably permanent by etching,
engraving or the like.
Immediately after the sample 11 is taken (and before
significant VOC evaporation can occur), the barrel 13
with the possibly-contaminated soil sample 11 inside is
then sealed as described above and the tool 10 set aside.
The overall length of the tool 10 may be two or three
times the length of the barrel 13 alone. Clearly,
provision of adequate storage and carrying space for
several dozen complete tools 10 becomes a significant
concern, especially at a remote field site 67 where
working conditions may be less than ideal. In a
preferred sampling tool 10, the handle 23 and ejector 29
may be removable from the barrel 13 and plunger 37,
respectively. When removed, the aperture 83 is plugged
for vapor retention using a plug 85 like that shown in
FIGURE 4. And, of course, "sample loaded" tools 10 can
be stored as is without removing the handle 23 and
ejector 29.
Referring to FIGURE 8, when all desired samples 11
have been taken, the "sample-loaded" tools 10 are used to
place soil samples 11 into vials 53 kept on site 67.
Such samples 11 are later analyzed at a laboratory. And
each sample 11 is placed into a vial 53 marked with the
Wo95/3l707 21 8 9 8 5 ~ PCT~S9StOS830
. ~"~
-13-
same designator 81 as is marked on the tool 10 and on the
field sketch. The tool 10 thereby becomes the link
between a particular location 75 and a particular vial 53
and helps establish a sample "chain of custody".
Sample placement is by uncapping the barrel 13,
quickly inserting such barrel 13 into a vial 53 and
manipulating the ejector 29 to drive the sample 11 into
the vial 53 for virtually-immediate vial capping. In a
highly preferred version, the tool barrel 13 has an
outside diameter not in excess of, and preferably very
slightly less than, about 25mm. Since many types of
appropriately-sized lab vials 53 have a mouth diameter of
25mm or greater, such a barrel 13 can be readily inserted
into such vials and, of course, into vials 53 having
larger mouths. As illustrated in FIGURE 8, an
appropriately-sized barrel 13 closely fits the diameter
of the vial mouth 87 to help prevent vapors from
escaping.
Referring also to FIGURES 11 and 12, another aspect
of the invention involves a tool-like cartridge 113 for
preserving a core-like soil sample 11 after such sample
11 has been removed from a site 67 possibly contaminated
with VOC. A major advantage of the cartridge 113 is that
it can be used "on-site" to quickly and completely seal a
possibly-contaminated soil sample 11 within such
cartridge 113 immediately upon withdrawal of the tool
barrel 13a from the soil. Another advantage of such
cartridge 113 is that it can be carried "sans handle" for
space-saving transportation of the confined soil sample
11 to a laboratory.
The invention has a number of new features
configured and arranged to preserve the integrity of a
soil sample 11 after it has been extracted and up to
actual analysis. The new cartridge 113 has a generally
cylindrical barrel 13a with a mouth portion 17a bounded
by a relatively thin knife-like edge 21a so that the
cartridge 113 may be more easily urged into the earth.
W O 9~t31707 218 9 8 5 5 i PCTtUS95/05830
At its proximal end 115 opposite the mouth portion 17a,
the barrel 13a has an attachment portion 117 to which the
threaded end 119 of a handle 23a is attached during
actual sample extraction.
The barrel attachment portion 117 and the distal end
119 of the handle 23a are compatibly threaded. The
handle 23a can thereby be easily attached to the barrel
13a for sampling and thereafter just as easily detached
from such barrel 13a for transporting the sample.
The structural arrangement that seals the proximal
end 115 of the cartridge 113 is as follows. The
attachment portion 117 has a "smooth-bore" opening 121
through it and within the barrel 13a is a plug 123 having
an imperforate, disc-like face plate 125 and a stud 127
of reduced diameter ext~n~;ng from such plate 125. The
end 129 of stud 127 is externally threaded and also has a
threaded interior cavity 131. The plug 123 seals an end
115 of the barrel 13a during sample extraction and
transport and, as described in more detail below, is
later used to expel the soil sample from the cartridge
113.
A sealing member 133 such as a resilient O-ring is
interposed between the face plate 125 and the attachment
portion 117. After the stud 127 is inserted through the
opening 121, a retention device 135 such as a nut is
threaded to the stud 127. When the nut is tightened, the
O-ring is compressed and the opening 121 is sealed. And
there is a cover 137 on the attachment portion 117 as a
thread protector when a handle 23a is not attached.
Referring also to FIGURE 2, a cap 55 seals the mouth
portion 17a. As described above, the cap 55 has an 0-
ring 51a in a groove 61 and when the cap 55 is in place,
the O-ring 51a is compressed and seals against the mouth
portion 17a. Like the plug 123, such cap 55 prevents VOC
vapors from escaping from the cartridge 113 after sample
extraction, while the sample 11 is being transported to a
2t8g8~
WO95/31707 PCT~S95/05830
-15-
laboratory and until the analyst is ready to remove the
cap 55 and expel the sample 11 into a vial for analysis.
Other aspects of the invention involve a method for
obtaining a soil sample using the unique tool-like
cartridge 113 described above. Such method includes the
steps of providing a generally-cylindrical cartridge 113
having an open mouth portion 17a and a proximal end 115
sealed by a removable plug 123.
In preferred practice (and prior to shipment to the
customer), the cartridge manufacturer or distributor
installs the removable plug 123 by inserting the stud 127
through the opening and tightening the nut. If the
prospective user, e.g., an environmental engineering
company, has not earlier obtained a suitable handle 23a,
such handle 23a is ordered to be supplied with the
cartridge 113 or with a group of cartridges 113.
As the user prepares to take a soil sample, the end
119 of the removable handle 23a is attached to the
cartridge 113. The cartridge 113 then used to "core out"
and extract a soil sample 11.
Immediately following sample extraction, the mouth
portion 17a is closed, preferably by applying a cap 55 to
such mouth portion 17a. For optimum sealing, the
applying step includes compressing the resilient seal 51a
between the cap 55 and the mouth portion 17a. And the
handle 23a is detached but end closure and handle
detachment may be in either order but is preferably done
in the order described. Using such method, the soil
sample 11 and any VOC therewith is quickly "captured" in
the cartridge 113 for preservation, transport and later
analysis.
In other aspects of the method, the handle detaching
step is followed by the steps of transporting the
cartridge 113 for analysis and, when ready to analyze the
sample, moving the plug 123 along the cartridge barrel
13a toward its mouth portion 17a to expel the soil sample
from the cartridge 113. To move the plug 123, a rod-like
WO95/31707 PCT~S9S~S830
21898~ -16-
implement 139 (as shown in FIGURE 13) is provided for
applying force to the plug 123. The implement 139 is
coupled to the plug 123 by screwing the implement end 141
into the threaded interior cavity 131 of the plug 123.
The plug 123 and soil sample ll are then pushed out.
It has been found that the new cartridge 113 and the
method of its use are major advances in soil VOC analysis
since the soil sample need not be removed from the
cartridge 113 to be transported. And the integrity of
the sample 11 (and any VOC vapors contained therein) is
well maintained by the sealing means 51a, 133 at each end
of the cartridge 113. That is, VOC vapors are
substantially prevented from escaping and contaminants
are prevented from entering.
And those are not the only advantages. In practice,
users of the cartridge 113 are often repeat purchasers
thereof and have obtained a handle 23a with their first
cartridge purchase. Similarly, the analyzing laboratory
has obtained a rod 139 to urge the plug 123 toward the
cartridge mouth portion 17a. Thereafter, it is necessary
to supply only cartridges 113 to the user, to ship only
soil-containing cartridges 113 to a laboratory and to
ship the dirty cartridges 113 back to a cleaning site for
cleaning and later re-use. That is, no handle 23a or
implement 139 need accompany the cartridge. The
aggregate saving in shipping space is very significant.
While the principles of this invention have been
described in connection with specific embodiments, it is
to be understood clearly that such embodiments are
exemplary and not limiting.
