U.S. patent application number 14/229054 was filed with the patent office on 2014-07-31 for liquid analysis apparatus.
This patent application is currently assigned to LAMOTTE CHEMICAL PRODUCTS COMPANY. The applicant listed for this patent is LAMOTTE CHEMICAL PRODUCTS COMPANY. Invention is credited to James W. Egan, JR., Horacio Kido, Jim Norton.
Application Number | 20140212336 14/229054 |
Document ID | / |
Family ID | 50233469 |
Filed Date | 2014-07-31 |
United States Patent
Application |
20140212336 |
Kind Code |
A1 |
Kido; Horacio ; et
al. |
July 31, 2014 |
Liquid Analysis Apparatus
Abstract
A rotary analytical device for use with a reagent cartridge. The
cartridge may have a housing, an axis, analysis chambers spaced
from and located circumferentially about the axis, and a
magnetically movable element located in and movable within each
analysis chamber to mix fluid in the analysis chamber. The rotary
analytical device may have a housing with a cavity having an axis,
an impeller extending into the cavity and rotatable about the axis
to receive and rotate the cartridge, a motor to rotate the
impeller, at least one magnetic element near the cavity and offset
from the axis, a light source in the housing to direct a beam of
light into the cavity and through the analysis chamber of the
cartridge, and a light sensor to receive light from the analysis
chamber.
Inventors: |
Kido; Horacio; (Lake Forest,
CA) ; Norton; Jim; (Santa Ana, CA) ; Egan,
JR.; James W.; (Lynch, MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LAMOTTE CHEMICAL PRODUCTS COMPANY |
Chestertown |
MD |
US |
|
|
Assignee: |
LAMOTTE CHEMICAL PRODUCTS
COMPANY
Chestertown
MD
|
Family ID: |
50233469 |
Appl. No.: |
14/229054 |
Filed: |
March 28, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13611843 |
Sep 12, 2012 |
8734734 |
|
|
14229054 |
|
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|
Current U.S.
Class: |
422/82.09 ;
422/548 |
Current CPC
Class: |
B01L 3/5025 20130101;
G01N 33/1893 20130101; B01F 15/00318 20130101; B01F 13/0818
20130101; B01L 2400/0409 20130101; B01L 2300/0864 20130101; B01L
3/5027 20130101; B01L 2300/0819 20130101; B01F 11/0082 20130101;
B01F 11/0074 20130101; B01F 13/0059 20130101; B01L 2300/0803
20130101; G01N 21/03 20130101; G01N 21/78 20130101; B01L 2300/0829
20130101; B01L 2300/0867 20130101; B01L 3/502 20130101; B01L
2400/043 20130101; B01L 2400/0475 20130101; G01N 2021/0325
20130101 |
Class at
Publication: |
422/82.09 ;
422/548 |
International
Class: |
G01N 33/18 20060101
G01N033/18; B01L 3/00 20060101 B01L003/00 |
Claims
1. A rotary analytical device comprising: a housing having a cavity
formed therein, the cavity being defined by a bottom wall and at
least one side wall, the cavity having an axis; an impeller
extending into the cavity and rotatable about the axis; a motor
mounted within the housing and connected to the impeller, the motor
adapted to rotate the impeller; at least one magnetic element in
the housing at a location proximate to the cavity and offset from
the axis; at least one light source in the housing and arranged to
direct a beam of light into the cavity; and at least one light
sensor in the housing and arranged to receive light from the at
least one light source, the sensor being sensitive to light of a
color emitted by the light source.
2. A rotary analytical device according to claim 1, wherein there
are a plurality of magnetic elements mounted to the housing.
3. A rotary analytical device according to claim 2, wherein
magnetic elements are offset at equal distances from the axis, and
spaced apart circumferentially from one another.
4. A rotary analytical device according to claim 3, wherein the
housing includes a lid and a body portion, the lid being hinged to
the body portion, the cavity being locate in the body portion and
enclosed by the lid, and wherein some of the plurality of magnetic
elements are mounted in or below the bottom wall and the remainder
of the magnetic elements are mounted in the lid, the magnets in the
lid not being aligned vertically with the magnetic elements on the
bottom wall such that they are circumferentially spaced apart from
each other.
5. A rotary analytical device according to claim 4, in combination
with a cartridge mountable on the impeller with the cavity for
being rotated by the impeller, the cartridge comprising: a
cartridge housing having a central axis coincident with the axis of
the impeller; a plurality of analysis chambers in the housing, the
chambers being spaced apart from the axis and located
circumferentially about the axis; and a magnetically movable
element located in each analysis chamber and movable within the
analysis chamber, the element adapted to cause the mixing of fluid
in the analysis chamber.
6. A rotary analytical device according to claim 5, wherein the
magnetic elements are positioned in the housing so as to be
substantially near the magnetically movable elements of the
cartridge such that when the cartridge is rotated within the
cavity, as the magnetically movable element passes a magnetic
element, the magnetically movable element is attracted to or
repelled from the magnetic element.
7. A rotary analytical device according to claim 1, wherein there
are a plurality of said light sources spaced apart
circumferentially from one another and at substantially the same
radial distance from the axis of the cavity; and wherein there are
a plurality of light sensors, each light sensor being sensitive to
light received from one of the light sources.
8. A rotary analytical device according to claim 7, wherein there
are an equal number of light sources and light sensors, and wherein
the device is configured such that a light sensor analyzes light
only from a specific light source.
9. A rotary analytical device according to claim 8, further
comprising circuitry operative to measure time-varying light
intensities sensed by the plurality of sensors, associate the
intensities with ones of a plurality of locations on a cartridge
rotating on said impeller, and generate an output responsive to the
intensities at specific ones of the locations.
10. A rotary analytical device according to claim 9, wherein the
output is responsive to intensities at specific wavelengths and/or
to specific variations in intensity with wavelength at the
locations.
11. The analytical cartridge of claim 5, wherein the analysis
chamber comprises a first chamber section containing the
magnetically movable element and a second chamber section fluidly
connected with the first chamber section, and wherein the fluid
connection between the first and second chamber sections includes
an axial slot that is narrower than a minimum dimension of the
magnetically movable element.
12. The analytical cartridge of claim 11, wherein the analysis
chamber contains a photometric reagent, and wherein the housing
above and below the second chamber section includes a portion that
is transparent to light of at least one wavelength appropriate for
photometry of the reagent.
13. The analytical cartridge of claim 12, further comprising at
least one reference chamber without a magnetically movable
element.
14. The analytical cartridge of claim 12, comprising a distribution
gallery located radially inward from and fluidly connected to the
analysis chambers, the distribution gallery adapted to distribute a
liquid to be analyzed to the analysis chambers through centrifugal
force upon rotation of the cartridge about the axis.
15. The analytical cartridge of claim 14, wherein the distribution
gallery has an inlet for receiving the liquid to be analyzed at one
end, and is connected to an overflow chamber at the other end; and
wherein the fluid connection with the analysis chambers includes a
plurality of channels located between the inlet and the overflow
chamber and extending radially from the distribution gallery, each
channel connected to an analysis chamber.
16. The analytical cartridge of claim 13 wherein the analysis
chambers and the at least one reference chamber are evenly spaced
circumferentially about the axis, wherein the at least one
reference chamber does not have a first chamber section, and
wherein the overflow chamber is larger than one of the analysis
chambers, and the overflow chamber and the at least one reference
chamber together occupy the same space as two said analysis
chambers.
17. The analytical cartridge of claim 12, wherein the magnetically
movable element is a ball bearing.
Description
RELATED APPLICATION
[0001] This application is a divisional of U.S. application Ser.
No. 13/611,843, which is incorporated herein by reference in its
entirety.
BACKGROUND OF THE INVENTION
[0002] It is frequently desired to analyze a liquid to determine
the presence and concentration of analytes such as minor
constituents and/or contaminants. In many instances, several
different tests may be run on one or more portions of a single
liquid sample, to detect and measure different constituents. For
many common tests, reagents are available that provide an almost
instantaneous result by changing either hue or intensity of color
in response to a specific constituent in the liquid. An example is
a swimming-pool test kit, which typically provides from two to six
different reagents that test for common factors such as chlorine or
bromine content, pH, and hardness of the water.
[0003] However, such test kits conventionally require the user to
fill a specific amount of water into a test container, add a
specific amount of reagent, judge the intensity or hue of the
resulting color against a reference chart by eye, and repeat the
whole process for each test that it is desired to carry out. If the
test results are not within a desired range, the user must then
manually calculate the amounts of chemicals to add to the swimming
pool to adjust its condition to the desired range. That is time
consuming, messy, and not very accurate. The situation is even
worse for a pool supply store, where the store staff are frequently
asked for assistance by a pool owner whose pool chemistry has gone
wrong in a way that the owner cannot himself correct. The store
staff may then need to conduct a much larger range of tests, and to
convert the results of the tests to quantities of various chemicals
to be added to the pool.
[0004] Similar issues occur in other businesses and industries. For
example, in brewing, trace constituents of the water used can not
only directly affect the flavor and quality of the brewed beverage,
but also affect the behavior of the yeast and therefore the success
and result of the brewing process. Other businesses in which a
battery of tests have to be performed fairly frequently, so that
similar issues occur, include aquaria, aquaculture, environmental
monitoring, and maintaining boilers and coolers.
[0005] There is, therefore, a need for apparatus and methods that
make it possible to test a liquid sample for several different
properties, for example, for the presence or absence of several
different analytes, in a single operation, with a minimum of mess,
and to obtain the results of the tests automatically, without
relying on human judgment.
SUMMARY OF THE INVENTION
[0006] One embodiment of the invention provides a rotary analytical
device comprising a housing having a cavity formed therein, the
cavity being defined by a bottom wall and at least one side wall,
the cavity having an axis, an impeller extending into the cavity
and rotatable about the axis, a motor mounted within the housing
and connected to the impeller, the motor adapted to rotate the
impeller, at least one magnetic element in the housing at a
location proximate to the cavity and offset from the axis, at least
one light source in the housing and arranged to direct a beam of
light into the cavity, and at least one light sensor in the housing
and arranged to receive light from the at least one light source,
the sensor being sensitive to light of a color emitted by the light
source.
[0007] Further embodiments of the invention provide combinations of
a rotary analytical device and an analytical cartridge co-operating
with the rotary analytical device, and methods of analysis using
such rotary analytical devices, such analytical cartridges, and
such combinations of a rotary analytical device and an analytical
cartridge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above and other aspects, features, and advantages of the
present invention may be more apparent from the following more
particular description of embodiments thereof, presented in
conjunction with the following drawings. In the drawings:
[0009] FIG. 1 is a schematic view of an embodiment of a liquid
analysis apparatus.
[0010] FIG. 2 is a perspective view of a rotary analyzer forming
part of the liquid analysis apparatus of FIG. 1.
[0011] FIG. 3 is a top plan view of a cartridge used in the rotary
analyzer of FIG. 2.
[0012] FIG. 3A is a cross-section view of an analysis chamber and
agitator chamber.
[0013] FIG. 3B is a view similar to FIG. 3A in a different position
in operation.
[0014] FIG. 4 is a view similar to FIG. 3A of an alternative
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] A better understanding of various features and advantages of
the present methods and devices may be obtained by reference to the
following detailed description of illustrative embodiments of the
invention and accompanying drawings. Although these drawings depict
embodiments of the contemplated methods and devices, they should
not be construed as foreclosing alternative or equivalent
embodiments apparent to those of ordinary skill in the subject
art.
[0016] Referring to the drawings, and initially to FIG. 1, one form
of liquid analysis apparatus, indicated generally by the reference
number 10, comprises a rotary analyzer, indicated generally by the
reference number 12 and shown in more detail in FIG. 2, connected
to a computer 14. Computer 14 may be a conventional personal
computer or similar device suitably programmed, and may comprise,
among other equipment, a processor or controller 16, input and
output devices such as a keyboard 18 and a monitor 20, random
access memory (RAM) 22, read-only memory (ROM) 24, magnetic disks
or other long-term storage 26, and an interface 28 to an external
network 30 or other communications media. The interface 28 may also
provide a connection from the computer 14 to the rotary analyzer
12.
[0017] Referring now also to FIG. 2, the rotary analyzer 12
comprises a base 50 defining a recess 52 in its upper surface, and
a lid 54 hinged to base 50 and defining a generally cylindrical
recess 56 in its lower surface. When the lid 54 is closed, it
preferably fits into recess 52. A spindle 58 projects through the
lower surface of the recess 52 and is received in the recess 56
when the lid 54 is closed. The spindle 58 has a flat surface 60 on
one side. Below the bottom of the recess 52, the spindle 58 is
connected to and driven by a motor 62, and is preferably connected
to a rotary encoder 64 or similar device by which its rotational
position can be monitored. However, as will become apparent after
review of the following description, other well known mechanisms
can be used to provide rotational position signals to the
apparatus.
[0018] In the embodiment shown, four light sources, preferably
light emitting diodes (LEDs) 68, 70, 72, 74 are mounted in the
underside of the lid 54 in the top of recess 56. The LEDs 68, 70,
72, 74 may be of different colors, for example, respectively red,
yellow, green, and blue. Four light detectors, such as photodiodes
or other photoelectric transducers 76, 78, 80, 82, are mounted in
the bottom of the recess 52, each facing a respective one of LEDs
68, 70, 72, 74. Each transducer 76, 78, 80, 82 may be provided with
a dichroic or other band-pass filter or otherwise optimized to be
selectively sensitive to the light from its respective LED. It is
also contemplated that the light sources could be located on the
same side as the detectors (e.g., the bottom of the recess) with a
reflective surface mounted on the opposite side of the recess
(e.g., on the lid).
[0019] In other embodiments, more or fewer light sources, and/or
light sources of different colors, which may include infrared
and/or ultraviolet, may be used. In other embodiments, other sorts
of light sources, which may include a broadband source such as an
incandescent lamp, may be used.
[0020] A first permanent magnet 84 is mounted in the underside of
lid 54 between two of the LEDs. A second permanent magnet 86 is
preferably mounted in the bottom of recess 52, between two of the
transducers, spaced apart from the first magnet 84. The LEDs 68,
70, 72, 74, the transducers 76, 78, 80, 82, and the magnets 84, 86
are preferably all at the same radius from the axis of rotation of
spindle 58, however it is contemplated that the magnets can be
located at a different radius depending on the construction of the
cartridge.
[0021] An indicator lamp 88 may be provided on the exterior of the
rotary analyzer 14, in a position where it is easily visible even
with lid 54 closed. An interlock switch 90 may be provided to
detect when lid 54 is closed.
[0022] A processor or controller 94 suitably programmed is
provided, and receives inputs from the transducers 76, 78, 80, 82,
the rotary encoder 64, and interlock switch 90, and controls the
LEDs 68, 70, 72, 74, the motor 62, and the indicator light 88. The
interlock switch 90 is preferably configured to provide signal to
the processor or controller 94 for detecting when the lid is closed
in order to prevent activation of the spindle 58 when the lid is
not in its closed position. The indicator light 88 preferably is
illuminated when the analyzer is active or when the testing is
complete.
[0023] Referring now also to FIG. 3, one form of cartridge,
indicated generally by the reference number 100, comprises a molded
body with a generally flat lid or top surface 101. Cartridge 100
comprises a central opening 102 that is preferably D-shaped an
configured to engage with the flat 60 on the spindle 58, so that
when the cartridge 100 is mounted on the spindle 58 the orientation
of the cartridge 100 relative to the rotary encoder 64 is fixed and
predetermined. It is contemplated that the opening 102 can be any
suitable non-circular shape designed to mate with a complementary
spindle shape.
[0024] At least partially surrounding the central opening 102 is an
annular filling chamber 104, which in one embodiment extends around
the opening about 330.degree. of the circumference of the
cartridge. At one end of the filling chamber 104 preferably
includes a radially inward extension 106, that includes a filling
port 108, which is the an opening through the lid of cartridge 100.
Water can be injected through filling port 108 using a conventional
syringe (not shown) into filling chamber 104. Visible indicia may
be molded into or placed on the lid of the cartridge 100, for
example, to point out where the filling port 108 is located and/or
to indicate a point to which the filling chamber 104 should be
filled.
[0025] At the end of the filling chamber 104 remote from the
filling port 108, a transfer passage 110 extends radially outward
to a distribution gallery 112, which in the illustrated embodiment
almost completely encircles the cartridge 100 outside the filling
chamber 100. Of course it is contemplated that multiple passages
100 can communicate with multiple galleys 112. From the
distribution gallery 112, a plurality of spouts or channels 114
extend radially outward. From the end of the distribution gallery
112 furthest from the transfer passage 110, there is preferably
located an overflow passage 116 that extends radially inwards, and
opens into the central opening 102 through the flat side of the
D-shaped opening.
[0026] Outside the distribution gallery 112 are several analysis
chambers 120, each with an associated agitator chamber 122, at
least one comparison chamber 124, and an overflow chamber 126. The
analysis chambers 120, comparison chamber 124 and overflow chamber
126 are each connected to the distribution galley through one of
the channels 114. The analysis chambers 120 are located
circumferentially on a circle with a radius that corresponds to the
radial location of the LEDs 68, 70, 72, 74, the photoelectric
transducers 76, 78, 80, 82, and preferably the magnets 84, 86. The
analysis chambers 120 are preferably equally sized and evenly
spaced, although that is not necessary in the present invention. In
the cartridge 100 shown in FIG. 3, there are ten analysis chambers
120, spaced at intervals of approximately 30.degree. ( 1/12 of the
circumference of the cartridge). The comparison chamber 124
occupies an eleventh position, and in the illustrated embodiment is
about the same size as an analysis chamber, but does not have an
associated agitator chamber. The overflow chamber 126 occupies the
twelfth position, and is larger than the analysis chambers. The
overflow chamber 126 uses up the space that is available where the
overflow and comparison chambers do not have agitator chambers. The
overflow chamber 126 is at the same end of distribution gallery 112
as the overflow passage 116.
[0027] As shown in FIG. 3A, the analysis chambers 120 are elongated
in the circumferential direction, and extend between the top and
bottom of the cartridge 100, closed off by the lid 101. The
agitator chambers 122 are preferably generally circular in
cross-section, and extend between the top and bottom of the
cartridge 100, closed off by the lid 101. Each agitator chamber 122
is connected to its associated analysis chamber 120 by a slot 128
preferably extending between the top and bottom of the cartridge.
Each agitator chamber 122 contains an agitator 130 preferably in
the form of a magnetizable stainless steel ball hearing (BB) that
is small enough to move freely along the agitator chamber 122
between the positions shown in FIG. 3A and FIG. 3B, but large
enough to displace water like a piston when it does so, and too
large to pass through the slot 128.
[0028] The top and bottom faces or surfaces of the cartridge 100
above and below the analysis chambers 120 are preferably made
smooth, flat, and clear, so as to permit the transmission of light
with minimal absorption and scattering.
[0029] In a ready-for-use condition of the cartridge 100, each
analysis chamber 120 contains a predetermined amount of a selected
reagent 121. Preferably, the reagents 121 are introduced into the
analysis chambers 120 in liquid form and dried or allowed to dry
onto the bottoms of the analysis chambers, thus immobilizing the
reagents so that they do not move outside their respective chambers
during shipping. Alternatively, the reagents could be dried prior
and then metered into the chambers. Once the reagents and the
agitators 130 have been introduced into the cartridge 100, the lid
101 is attached, for example, by sonic welding. In one example of a
cartridge for analyzing swimming-pool water, the reagents are
suitable for measuring one or more of the following, preferably
all: free chlorine/bromine; total chlorine; total alkalinity; pH;
calcium and/or magnesium hardness (at two different ranges);
copper; iron; borate; and cyanuric acid. In another example,
biguanide and biguanide shock measuring reagents are substituted
for the chlorine and bromine tests, and the cyanuric acid test is
omitted.
[0030] In use, a measured amount of water or other liquid to be
analyzed is injected into the filling chamber 104 through the
filling port 108. The amount may be measured by filling the filling
chamber 104 until the water reaches a visible filling mark, for
example, until the boundary between the area of the chamber 104
furthest from the fill port 108 is filled and at a location
underneath or between lines molded on the cartridge 100. As liquid
is injected in the filling chamber 104, air in the chamber is
displaced through the overflow passage 116. Other mechanisms for
venting air can be provided, such as a vent port on the
distribution gallery 112. The cartridge 100 is then placed over the
spindle 58, with the flat surface 60 on the spindle 58 engaging the
flat side of D-shaped opening 102 in the cartridge 100.
[0031] A cover 140 is then preferably placed over cartridge 100.
The cover 140 may be made from an opaque or black material or
suitably coated to limit and absorb stray light from the LEDs 68,
70, 72, 74, and may be made of a strong plastic to protect the
analyzer 12 if there is any failure of the cartridge 100. The cover
140 may have openings aligned with the analysis chambers 120, and a
D-shaped central opening that engages the flat 60 of spindle 58 so
that the openings in the cover 140 remain in alignment with the
analysis chambers 120. The cover 140 may be omitted. In an
alternative embodiment, another provision may be made for reducing
stray light. For example, the spindle 58 may be provided with a
flat plate on which the cartridge 100 rests, and which has openings
aligned with the analysis chambers 120.
[0032] Once the cartridge is mounted, the lid 54 is closed, and the
analyzer 12 is activated, either by a control on the analyzer
itself or by a command signal from a computer 14. The motor 62
rotates the spindle 58, which rotates the cartridge 100 at a speed
suitable for generating sufficient centrifugal force to cause the
liquid to flow outward from the filling chamber 104 through the
transfer passage 110 to the distribution gallery 112. The liquid
flows along the distribution gallery 112, and outward, again by
centrifugal force, through the channels 114 to fill the analysis
chambers 120 and the comparison chamber 124. Any excess liquid will
pass through the whole length of the distribution gallery 112 into
the overflow chamber 126. Any excess liquid should remain in
filling chamber 104 or distribution galley 112, because the outlet
of overflow passage 116 is radially inward from the distribution
galley, closer to the center of rotation.
[0033] Once the liquid has been distributed to the analysis
chambers 120, the motor 62 continues to rotate the cartridge 100.
As each agitator chamber 122 passes the magnets 84, 86, the
agitator 130 is attracted by the magnets and moves alternately up
and down within the agitator chamber 122, between the positions
shown in FIGS. 3A and 3B, depending on the magnet it passes. The
movement of the agitator 130 causes an oscillating circulation of
liquid within the agitator chamber 122 and its associated analysis
chamber 120. The circulation of liquid assists in the dissolving or
suspension of the reagent 121 into the liquid, and facilitate the
even mixing of the reagent 121 throughout the liquid in analysis
chamber 120.
[0034] Each reagent is preferably formulated using known techniques
such that it forms an appearance such as hue, intensity of color,
or opacity that is detectable or measurable by light, depending on
the presence, absence, or concentration of the analyte that each
reagent is intended to detect. In an embodiment, different reagents
121 in the different analysis chambers 120 form different colors,
depending on the concentration of the analyte that each reagent is
intended to detect.
[0035] Each color may be measured by the absorption of the light
from one or more of the LEDs 68, 70, 72, 74 before it reaches its
respective transducer 76, 78, 80, 82, or alternatively, by the
amount of light that passes through to the respective transducer.
The colors may vary in hue, intensity, or both. For example, one
standard reagent for measuring chlorine concentration produces a
pink color that becomes darker as the chlorine concentration
increases, and may be measured by the absorption of blue light from
the LED 74. For example, one standard reagent for measuring pH
varies in hue from yellow at low pH to red at high pH, and may be
measured by the absorption of light from the yellow LED 70 or the
green LED 72. A reagent that varies in hue may also be measured by
the difference between absorptions of light from light sources of
two different colors.
[0036] Errors caused by variation in the intensity of the light
emitted by the LEDs, and lack of transparency of the initial liquid
samples, may he corrected by measuring the light transmitted
through the reference chamber 124. The light of each color
transmitted by each chamber may be identified by synchronizing the
time-varying output from the transducers 76, 78, 80, 82 with the
timing information from the rotary encoder 64 as the spindle 58
rotates.
[0037] In an embodiment, the processor 94 repeatedly samples the
measured light intensity data from the transducers 76, 78, 80, 82.
The processor 94 discards readings that do not match one of the
analysis chambers 120 or the reference chamber 124. Merely by way
of example, the processor 94 may sample the transducers 400 times
per revolution of the cartridge 100, and extract 4 readings for
each analysis chamber 120 per revolution. The readings are then
averaged over several revolutions, and a matrix of 11.times.4
averaged readings is transmitted by the processor 94 to the
computer 14. The computer 14 is programmed with calibration data
for the set of reagents 121 in the cartridge 100, and converts the
light intensity data into concentrations of the various analytes.
Programs for converting the light intensities into analyte
concentrations, including databases of the characteristics of
standard reagents, are commercially available and, in the interests
of conciseness, need not be further described here. The computer 14
may display the concentrations on screen 20. While the analyzer is
shown having a processor 94 mounted within it, it is also
contemplated that all the processing may occur at the computer.
Alternatively, the processor 94 can be programmed to provide all
the analysis necessary and provide the results to the computer or
other display device.
[0038] Instead, or in addition, where the liquid sample being
analyzed has a desired or ideal condition (as is the case, for
example, with swimming pool water) the computer 14 may be
programmed with a data file of available treatments to adjust the
condition. Optionally, relevant properties of a source of the
liquid sample being analyzed may also be stored on the computer 14
or input during the analysis, and the computer 14 may then generate
a prescription for treatments to correct any problem detected by
the analysis.
[0039] For example, if the sample being analyzed is water from a
swimming pool being analyzed at a pool supplies store, one
important piece of information is the size of the pool. If the
analysis shows that the water is outside a desirable range for one
or more analytes in the specific size pool, the computer 14 can
then generate a list of specific quantities of select pool
chemicals that are in stock in the store and needed to correct the
results of the analysis. Because different brands of chemicals may
come in different formulations, container sizes, and
concentrations, that typically may require at least a separate data
file for each brand.
[0040] As an example of suitable dimensions, for a water analyzing
apparatus for swimming-pool water, a cartridge as shown in FIG. 3
may be approximately 23 mm ( 15/16 inch) in radius to the centers
of the analysis chambers, and approximately 12 mm (1/2 inch) high.
The amount of water used may be from 2.7 to 2.9 ml. The cartridge
may be rotated at around 2300 rpm to distribute the water to the
analysis chambers 120 and the reference chamber 124 and to expel
bubbles, and then at a maximum of 4500 rpm to ensure proper
transfer of the water from the filling chamber to the reaction
chambers, and at 300 rpm to obtain the optimum pumping action from
the agitators. The rotation is continued for a period sufficient to
allow the reagents to become dissolved in the water, to react with
their respective analytes, and for the color or other measurable
optical property to develop. It is presently believed that an
analysis of swimming pool water of acceptable quality can be
obtained in less than a minute from when rotation starts.
[0041] It is contemplated that the cartridge my include indicia,
such as a bar code, RFID tag, or other form of information that can
be read, such as with a scanner or reader mounted in the analyzer,
which determines the reagents that are stored in the cartridge
being analyzed. This permits an analyzer to be used with multiple
cartridges, without the user having to input anything. However, it
is also contemplated that the user can select the sample being
analyzed (e.g., pool water, water for beer brewing process, etc.)
directly on the computer. The computer would use the information
for purposes of selecting the appropriate data file for analyzing
the sample data transmitted from the analyzer.
[0042] Referring now also to FIG. 4, an alternative embodiment of
the cartridge 100' is similar to that described above except that,
in place of slot 128, the analysis chamber 120 and the agitator
chamber 122 are separated by a solid septum 132, with apertures
134, 136, at both ends. The cartridge 100' may be used in the same
way as the cartridge 100. In use, movement of agitator 130 up and
down within agitator chamber 122 causes liquid to flow in and out
through apertures 134, 136 alternately, resulting in a
reciprocating flow within analysis chamber 120. The reciprocating
flow causes turbulence within the analysis chamber 120 that assists
in dissolution and distribution of the reagent.
[0043] Although specific embodiments have been described, various
modifications are possible without departing from the spirit of the
invention or the scope of the appended claims, and features of the
different embodiments may be combined into one embodiment.
[0044] For example, although the agitators have been described as
stainless steel ball bearings that are attracted to the magnets 84,
86, the agitators could instead also be magnets. If the agitators
are elongated so that they cannot rotate within their chambers,
they could be magnetically polarized so as to be repelled, instead
of attracted, by one or more of magnets 84, 86. It is presently
preferred to provide two magnets 84 and 86, so that agitators are
positively driven both up and down once per revolution. However,
more magnets could be provided, or in some circumstances there
could be only a single magnet driving the agitators upwards, with
the agitators being returned by gravity.
[0045] In the cartridges 100, 100' shown in the drawings, the
analysis chambers 120 and the reference chamber 122 are evenly
spaced in a circle around the circumference of the cartridge. Other
arrangements are possible. For example, there could be two
concentric circles of analysis chambers.
[0046] The cartridge shown in FIG. 3 is intended to be disposable,
and may be fabricated by gluing or welding a generally flat lid on
a molded body. However, the cartridge could instead be reusable, in
which case the lid may be removable to permit cleaning and
recharging of the reagents in the analysis chambers.
[0047] It would be possible to omit the rotary encoder 64, and use
the signal from one or more of the LEDs and transducer pairs to
provide a rotary encoder input to the processor 94. However,
because the reagents in the analysis chambers 120 will cause the
signals from the transducers 76, 78, 80, 82 to vary, a dedicated
encoder 64 may give more reliable, and more easily interpreted,
signals.
[0048] As shown in the drawings, the LEDs 68, 70, 72, 74, the
photoelectric transducers 76, 78, 80, 82, the magnets 84, 86, the
cartridge analysis chambers 120, the cartridge agitator chambers
122, and the cartridge reference chamber 124 are all centered on a
single rotational cylindrical surface centered on the axis of
spindle 58. Other arrangements are possible. For example the
magnets and agitators could be on one cylinder, and the LEDs,
analysis and reference chambers, and transducers could be on
another cylinder of different radius. One or both of those
cylindrical surfaces could instead be conical. The magnets 84, 86
do not need to be exactly aligned with the agitator chambers 122,
provided they are near enough to produce the desired motion of the
agitators 130.
[0049] While the analyzer is shown having a processor 94 mounted
within it, it is also contemplated that all the processing may
occur at the computer. Alternatively, the processor 94 can be
programmed to provide all the analysis necessary and provide the
results to the computer or other display device.
[0050] Furthermore, while the figures show the analyzer connected
directly to the computer, it is contemplated that the connection
could be through an internet connection, thus permitting samples to
be run in the analyzer at a location that is remote from the
computer than analyzes the data and provides the results.
[0051] Accordingly, reference should be made to the appended
claims, rather than to the foregoing specification, as indicating
the scope of the invention.
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