Patent Publication Number: US-2023152238-A1

Title: Multiple strip reader

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application derives priority from U.S. provisional application Ser. No. 63/279,726 filed Nov. 16, 2021. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to chemical test equipment in general, and more specifically to test strip readers. 
     2. Description of the Background 
     Test strips are a well-known media to test for the presence of particular chemical species in the air, pools, smoke stacks, water, and the like. These test strips are typically single-use disposables and/or consumables provided in bulk a container, typically a plastic vial with removable or flip-top cap. 
     For example, pool maintenance requires periodic regular testing of pool water and careful maintenance by chemical additives. The testing and balancing of swimming pool water can be a difficult process for the owner. There are myriad test kits available with different capabilities. At minimum a suitable test kit will test for available chlorine, cyanuric acid, pH, total alkalinity, and calcium hardness. Reagent test strips are a very common testing modality. Water test strips usually have a plurality of reagent test areas, each test area undergoing a color change in response to contact with a particular chemical constituent. The presence and concentrations of these constituents of interest can be determined by a colorimetric analysis of the color changes undergone by the test strip. Usually, this analysis involves a color comparison between the test area or test pad and a color standard or scale. 
     A variety of conventional test strip reading instruments exist which can determine the color change of a test strip. 
     U.S. Pat. No. 6,614,530 to Duez et al. (Biophotonics S.A.) issued Sep. 2, 2003 shows a method for the colorimetric measurement of a defined region on an image using a color camera, and discloses color-correction of tristimulus (R, G, B) values by selection of an area within an image in order to correct the imperfection in the homogeneity of the sensor and of the illuminant. 
     U.S. Pat. No. 5,408,535 to Howard, III et al. (Miles, Inc.) issued 18 Apr. 1995 shows a video test strip reader for evaluating test strips that uses a video imager or camera. The reader is connectable to a computer which choreographs imaging at the proper times and calculates the test results, such as the concentration of the constituents of interest. 
     U.S. Pat. No. 8,655,009 to Chen et al. (Teco Diagnostics) issued 18 Feb. 2014 shows a method and apparatus for color-based reaction testing of biological materials by capturing, in an uncalibrated environment, a digital image of an exposed test strip, together with an adjacently-located reference color chart or on-strip color chart. The image data specifically representing the individual test pads on the test strip, as well as the reference color blocks on the reference chart, are then located within the captured image, and compared to identify any color matches. 
     U.S. Pat. No. 8,703,057 to Morris (Hach Co.) issued 22 Apr. 2014 shows an electronic device for analyzing an aqueous solution with a housing configured to receive a single test strip. 
     U.S. Pat. No. 6,285,454 to Douglas et al. (Mercury Diagnostics, Inc.) issued 4 September 2001 shows an assay system that accurately docks a removable test strip with an optics system including an illumination LED and photodetector. 
     U.S. Pat. No. 8,142,722 to Morris et al. (Hach Co.) issued 27 Mar. 2012 shows a handheld portable electronic test strip tester. 
     U.S. Pat. No. 7,339,673 to Roman (Siemens Healthcare) issued 4 Mar. 2008 shows a miniature read head for a photometric test strip reader. 
     U.S. Pat. No. 8,145,431 to Kloepfer et al. (Advanced Medical Products GmbH) issued 27 Mar. 2012 shows a smart-phone-based body fluid test strip positioner. The test strip positioner positions a test strip in the FOV of the phone&#39;s camera lens to permit the camera to capture an image. A light source disposed within the positioner illuminates the analyte containing test strip to facilitate the capture of the image of the test strip. Software in the smart phone performs quantitative analysis. 
     United States Patent Application 20100254581 by Neeser et al. (Reveal Sciences) published 7 Oct. 2010 shows a method and apparatus for analyzing samples by obtaining an image using any mobile consumer device, storing and transmitting the image to a remote server, analyzing the image using an analysis software on a remote server, and sending the results of the analysis back to the consumer device. 
     U.S. Pat. No. 7,262,779 to Sones (Applied Vision Company, LLC) issued 28 Aug. 2007 shows a differential imaging colorimeter which utilizes a RGB color camera to provide accurate differential colorimetry. 
     United States Patent Application 20110275162 by Xie et al. (Alverix, Inc.) published 10 Nov. 2011 shows a low-cost assay test strip reader in which the strip is placed in a shuffle that moves it past a photodetector, which detects an optical signal at a single point. The movement of the test strip with respect to the detector allows it to scan a length of the test strip. 
     U.S. Pat. No. 9,569,858 to Babcock et al. (Taylor Technologies, Inc.) issued 14 Feb. 2017 shows a cloud-based system for water analysis using test strip readers each configured to obtain a digital image of a reagent test strip, normalize and analyze color information in the digital image by colorimetric analysis, and transmit colorimetric values to a cross-platform cloud-based system for analysis. 
     The foregoing references are configured to read a test strip and compare it to a fixed reference standard. What is needed is a way to read, reference positions, catalogue/index, calibrate, image, correct and analyze multiple test strips at a time using a single reader. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved test strip reader capable of reading, indexing, calibrating, correcting and interpreting multiple test strips at a time. 
     Yet another object is to provide a test strip reader with insertion carriage that makes it possible to load multiple test strips into an imaging station with minimal effort and maximum positional precision. 
     These and other features and benefits are achieved with an improved test-strip reader with insertion carriage that makes it possible to load multiple test strips into an imaging station with minimal effort and maximum precision. The multi-strip reader uses advanced lighting and imaging technology to make it possible to measure various reagents via multiple strips all at once including, for example, Free Chlorine (1C), total alkalinity (TL), cyanuric acid (CYA), total chlorine (CL), bromine (Br), and total alkalinity (pH) as typical of a pool or spa, thereby providing faster, more accurate, and more affordable test results. It maximizes ease and efficiency of use and minimizes risk of user error. 
     The insertion carrier loads a plurality of test strips at once to the imaging station, and the system automatically identifies them, references their positions, catalogues/indexes them, calibrates them, images them and analyzes them. The apparatus makes the loading and imaging process simple and foolproof for the user by a combination of hardware and software. The hardware employs a roller carriage with pneumatic spring-assist insertion and ejection. The carriage includes a test platform with a plurality of imaging beds to seat and position the strips, and a clamping mechanism to affix them therein. When the user places the test strips in the clamping mechanism and then in the carriage and initiates inward insertion into the enclosure, the remainder of the imaging and analysis process is completed automatically with an internal imaging assembly. The apparatus makes it possible to measure various reagents via multiple strips, up to eleven (11) tests in one minute including:
         Free Chlorine 0-10 ppm   Total Chlorine/Bromine 0-10 ppm   pH 6.4-8.4   Total Alkalinity 0-240 ppm   Total Hardness 0-800 ppm   Cyanuric Acid 0-300 ppm   Salt 0-5000 ppm   Borate 0-100 ppm   Copper 0-3.0 ppm   Iron 0-5.0 ppm   Phosphate 0-3000 ppb       

     For a more complete understanding of the invention, its objects and advantages, refer to the remaining specification and to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which: 
         FIG.  1    shows a top perspective view of a multiple test strip reader according to an embodiment of the invention. 
         FIG.  2    is an enlarged perspective view of the carriage  124 . 
         FIG.  3    is an enlarged top view of the test platform  140 . 
         FIG.  4    is a detailed view of a portion of clamp assembly  150 . 
         FIG.  5    is an enlarged perspective view of the roller tray  126  for guided insertion into imaging enclosure  122 . 
         FIG.  6    is a perspective view of the imaging unit  80 . 
         FIG.  7    is a front view of the microcontroller circuit board  40 . 
         FIG.  8    is a photograph of the composite image of four test strips. 
         FIG.  9    is a block diagram of the imaging and analysis process. 
         FIG.  10    is a graph of the 7-way pH color calibration curves 
         FIG.  11    is an example report of the statistically-enhanced color values uploaded and cataloged at step  460 . 
         FIG.  12    is a photograph of the clamp assembly  150  showing how a set of test strips is arranged into clamp assembly  150 . 
         FIG.  13    is a photograph of water vial  166  in use with clamp assembly  150 . 
         FIG.  14    is an exemplary loading fixture  138  shown holding a plurality of test strips  134  such that clamp assembly  150  can be slid over and clamp the protruding ends of test strips  134 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is multiple test strip reader configured to read a plurality of test strips at once and automatically identify them, reference their positions, catalogue/index them, calibrate them, image them, and analyze them, all with a single imaging unit. The device makes the loading and imaging process for multiple strips simple and foolproof for the user, allowing simultaneous measurement of various reagents via multiple strips. The multiple test strip reader employs a roller carriage with pneumatic spring-assisted insertion and ejection. The carriage includes a test platform with a plurality of imaging beds, one bed for each test strip, and a clamping mechanism to affix them therein. When the user places the test strips in the carriage with the clamping mechanism and initiates inward insertion into the enclosure, the remainder of the imaging and analysis process is completed automatically with an internal imaging assembly. The apparatus makes it possible to measure various reagents all at once including, for example, Free Chlorine (FC), total alkalinity (TA), cyanuric acid (CYA), total chlorine (TC), bromine (Br), Borate (Bo), Salt, Phosphate (PO4), Iron (Fe) and Copper (Cu), total hardness (TH) and pH as typical of a pool or spa. It maximizes ease and efficiency of use and minimizes risk of user error. For descriptive purposes the following components are given the following reference numerals in the FIGs: 
     
       
         
           
               
               
               
               
             
               
                   
               
               
                 Ref. 
                   
                 Ref. 
                   
               
               
                 No. 
                 Component 
                 
                   
                 
                 Component 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 2 
                 Multi-strip reader 
                 133 
                 Imaging beds 
               
               
                 10 
                 Enclosure 
                 134 
                 Test strips 
               
               
                 12 
                 Floor 
                 138 
                 Loading fixture 
               
               
                 14 
                 Upright section/chassis 
                 140 
                 Test platform 
               
               
                 16 
                 Top panel 
                 142 
                 Test beds 
               
               
                 22 
                 Wells 
                 143 
                 Guide posts 
               
               
                 24 
                 Wells 
                 144 
                 Platform 
               
               
                 32 
                 Illumination circuit board 
                 145 
                 Raised end posts 
               
               
                 40 
                 Microcontroller circuit board 
                 147 
                 Red positioning strip 
               
               
                 48 
                 Remote connector 
                 150 
                 Spring clamp assembly 
               
               
                 50 
                 Indicator panel 
                 151 
                 Lever 
               
               
                 52 
                 Openings 
                 152 
                 Spring 
               
               
                 80 
                 Cmos camera 
                 153 
                 Base 
               
               
                 81 
                 Indicator light 
                 154 
                 Pin 
               
               
                 83 
                 Light board 
                 156 
                 Carbon steel 
               
               
                 87 
                 Diffusers 
                 157 
                 Recesses 
               
               
                 121 
                 Extended tongue 
                 159 
                 Hinges 
               
               
                 122 
                 Imaging enclosure 
                 167 
                 Magnet 
               
               
                 124 
                 Rolling carriage 
                 165 
                 Water sample 
               
               
                 126 
                 Roller tray 
                 166 
                 Vial 
               
               
                 127 
                 Rails 
                 171 
                 Suction cups 
               
               
                 128 
                 Top shroud 
                 261 
                 Track 
               
               
                 129 
                 Bottom tray 
                 263 
                 Fixed flange 
               
               
                 131 
                 Raised flange 
                 264 
                 Catch 
               
               
                 132 
                 Apertures 
                 265 
                 Latch mechanism 
               
               
                 133 
                 Imaging beds 
                 266 
                 Gas spring 
               
               
                 134 
                 Test strips 
                 302 
                 Color calibration reference 
               
               
                 135 
                 Post 
                 304 
                 Grayscale references 
               
               
                 138 
                 Loading fixture 
                 402 
                 Microcontroller 
               
               
                 139 
                 Calibration label 
                 404 
                 USB connector 
               
               
                   
                   
                 406 
                 White LEDs 
               
               
                   
               
               
                     indicates data missing or illegible when filed 
               
            
           
         
       
     
       FIG.  1    shows a top perspective view of a multiple test strip reader  2  according to an embodiment of the invention. The multi-strip reader  2  generally comprises an enclosure  10  including a flat horizontal floor  12  secured to a work surface or table by four (4) corner-mounted suction cups  171 , and a forwardly-canted upright section  14  presenting an inclined top panel  16 . The top panel  16  is inclined at approximately a 30-degree angle so that when the multi-strip reader  2  is positioned atop a table, top panel  16  presents a flat yet frontally-inclined frontal exposure to a person standing directly in front. The top panel  16  is interrupted by a plurality of wells  22 ,  24  all comprising cylindrical recesses. Several wells  22  are shaped to conform to test strip vials (four being typical) and seat the containers within which the various types of unexposed test strips are provided. One or more wells  24  are shaped to conform to reagent bottles (two being typical) and seat the containers within which the various reagents are provided. The wells  22 ,  24  flank opposing sides of the top panel  16  and present a center space. An illumination circuit board  32  is suspended below the top panel  16  within the center space, also inclined at an angle, such that it is parallel to horizontal floor  12 . The illumination circuit board  32  defines an electronics compartment within which a microcontroller circuit board  40  is mounted atop pylons. A color CMOS camera  80  is mounted to the underside of circuit board  40  (as shown by arrow in  FIG.  7   ). One skilled in the art will understand that a CCD or other known or unknown digital imaging device could be used as well in place of CMOS camera  80 . The microcontroller circuit board  40  contains an indicator light  81 , in this case an LED, that is on the opposite side of circuit board  40  from CMOS camera  80 , and light created by indicator light  81  is visible to the user through translucent indicator panel  50  such that various combinations of color and durations of illumination create specific indications to a person standing directly in front regarding the status of the device. The microcontroller circuit board  40  is also connectable via remote connector  48 , here a universal serial bus (USB) connector, to any remote computer. All control inputs and imaging outputs to/from the microcontroller circuit board  40  are communicated via remote connector  48 . 
     Referring back to  FIG.  1   , the floor  12  includes an extended tongue  121  that provides a runway for a rolling carriage  124 . The color CMOS camera  80  mounted to the underside of circuit board  40  is oriented downward toward and parallel to test strips  134  seated in the rolling carriage  124 . The rolling carriage  124  conveys a plurality of test strips inward and outward to/from enclosure  10  atop the extended tongue  121  of floor  12 , and positions them in an internal imaging enclosure  122 . The carriage  124  is spring-loaded by a pneumatic cylinder (to be described) and retained by a latch (to be described) so that semi-automated opening allows the user to load another set of test strips thereon for imaging. The carriage  124  slides in and out of an imaging enclosure  122  that is affixed to the floor  12  inside main enclosure  10 . The top shroud  128  of the imaging enclosure  122  bears an array of parallel apertures  132  that expose the respective test strips to the color CMOS camera  80  mounted to the underside of circuit board  40 . In addition, the top shroud  128  of the imaging enclosure  122  bears a calibration array next to apertures  132  that provides both positioning indexing and color calibration for the CMOS camera  80  on circuit board  40 . When the consumer places test strips in the carriage  124  and initiates inward reinsertion into imaging enclosure  122 , the remainder of the imaging and analysis process is completed automatically with the CMOS camera  80  (to be described). 
       FIG.  2    is an enlarged perspective view of the carriage  124 , which includes a roller tray  126  mounted on bearing rollers for guided insertion into imaging enclosure  122 . The imaging enclosure  122  includes top shroud  128  attached to bottom tray  129 . The top shroud  128  is generally flat and arranged generally parallel to circuit board  40 , with a raised flange  131  and a plurality of elongate apertures  132  passing through the top shroud  128  and extending along a majority of the top shroud  128 . A test platform  140  rides atop the roller tray  126 . With additional reference to  FIG.  3   , the test platform  140  includes a plurality of imaging beds  133  for each test strip and holds the test strips  134  parallel to circuit board  40 . The carriage  124  also includes a spring clamp assembly  150  for loading and clamping the respective test strips onto the imaging beds  133 . The clamp assembly  150  includes a base  153 , and a lever  151  extending to a bridge  152  that is secured to the base  153  by opposing hinges  159 . As seen in  FIG.  4    a protruding post  135  on base  153  serves as a seat for a spring and as a stop limit when opening clamp  150 . The spring exerts a separating force between lever  151  and base  153  to close the bridge  152 , which magnetically latches closed vis-a-vis an embedded piece of carbon steel  156  located in base  153  beneath a magnet in bridge  152 . The entire clamp assembly  150  is magnetically indexed into the proper position on platform  140  by magnet  167 . Alternatively, magnets of opposite polarity could be used, with a magnet replacing the carbon steel element  156  embedded in platform  140 . 
     Movement of the carriage  124  into and out from the imaging enclosures  10 ,  122  is guided on the roller bearings atop tracks  127  and at the position furthest inside enclosures  10 , 122  there is a latch mechanism  265  that is of the push to close/push to open variety and secures carriage  124  into the correct position for subsequent imaging of test strips  134 . 
       FIG.  3    is an enlarged top view of the test platform  140  including imaging beds  133  for each test strip. The imaging beds  133  are flanked by raised guide posts  143  and raised end posts  145  for centering the strips. A red positioning strip  147  traverses the imaging beds  132  at the forefront. Referring back to  FIG.  1   , the red positioning strip  147  remains visible through the apertures  132  at the forefront and provides a positive indication to the CMOS camera  80  of full and correct insertion of roller tray  126  into enclosure  10 . 
       FIG.  4    is a detailed view of the base  153  of clamp  150  which includes a broad rectangular jaw  158  having a plurality of protruding hinges  159  for pivotal coupling to the bridge  152  of lever  151 . The jaw  158  is defined by a plurality of rectangular recesses  157  entering sidelong for seating and centering the distal ends of test strips, and the bridge  152  may likewise be formed with forward-projecting fingers that seat into recesses  157  to secure the test strips therein. The hinges  159  are received in complementary hinges on the bridge  152  of lever  153  and secured thereto by a hinge pin acting as a fulcrum and bearing a spring for bias. 
       FIG.  5    is an enlarged perspective view of the roller tray  126  mounted on bearing rollers atop tracks  127  for guided insertion into imaging enclosure  122 . The roller tray  126  runs along a track  261  into a fixed flange  263  mounted upright on floor  10 . A catch  264  projects forward from flange  263  toward the roller tray  126  and a push-latch rebound self-locking cabinet drawer latch mechanism  265  is secured atop roller tray  126  to engage the latch mechanism  264  when the roller tray  126  is fully closed. A gas spring  266  is secured at one end to the flange  263  as shown, and is internally secured at the other end to roller tray  126  to provide a resistance bias thereto. 
     A CMOS imaging unit  80  is mounted directly above the imaging enclosure  122  for imaging strips.  FIG.  6    is a perspective view looking up into the housing  14  of  FIG.  1    and showing the microcontroller circuit board  40  mounted therein, suspended atop a light board  83 . The CMOS camera  80  is surface-mounted to the microcontroller circuit board  40  and protrudes downward through a portal in light board  83 , exposed directly to the sampling tray  140  there beneath. The microcontroller circuit board  40  is connectable via remote USB connector  48  to any remote computer for control and sampling. The opposite side shown the microcontroller circuit board  40  bears at least one multi-color LED light  81  that shines back up through panel  50  of  FIG.  1   . The LEDs are positioned directly beneath the indicators  52  of  FIG.  1    and provide the illumination therefor, thereby providing sequential guidance and status to a person standing directly in front. 
     Specifically, the LEDs/indicator lights  81 / 52  flash green, yellow or red. In addition, the light board  83  bears four (4) white LEDs that shine into light diffusers  87  as shown, which in turn directs white light down toward the test strips for illumination thereof. The LED diffusers  87  help “smooth out” the light and minimize “hot spots”. The four diffusers  87  are translucent white frosted hemispherical panels and are fixed to light board  83  and used to spread light from the LEDs evenly inside the chassis  14 . 
       FIG.  12    shows how a set of test strips is loaded and clamped in place with clamp assembly  150 . 
     A user would then take clamp assembly  150  that is properly loaded with test strips  134  ( FIG.  12   ) and dip the strips simultaneously into a water sample. 
       FIG.  13    illustrates how the entire clamp assembly  150  fully loaded with test strips  134  is dipped into a specialized vial  166  containing a water sample  165 . Sample water  165  will be absorbed into pads  135  of test strips  134  and then the user removes clamp assembly  150  with the wetted test strips. Preferably, the sample water  165  that is contained within water sample vial  166  is segregated into a plurality of discrete chambers  167   a - c  so that a reagent or dye from one test strip  134  is isolated and does not affect the other test strips  134  or if the sample water  165  in a chamber is pre-treated for a particular analyte, this pre-treatment will not affect sample water  165  in other chambers. 
     After sampling, the user is then places clamp assembly  150  into place on rolling carriage  124  atop roller tray  126  such that clamp  150  is properly located and inserts the carriage  124  into imaging enclosure  122  until latch mechanism  265  engages with and holds catch  264 , at which point the test strips lie directly in the field of view of the illuminated CMOS camera  80  for full frontal illumination and imaging. In this imaging position the CMOS imager  80  images the strips without substantial glare interference to or from the illumination. The remote computer runs a software application that automatically triggers a still image frame from the CMOS imager  80 . This image includes all strips and test strip pads on the strip, as well as a calibration label  139  ( FIG.  2   ), and it is subjected to registration, calibration and colorimetric analysis as will be described. At the conclusion of the testing sequence the user pushes carriage  124  slightly further into enclosure  10  which activates the release cycle of latch mechanism  265 . Alternatively, it is contemplated to use magnetic latches or a variety of other well know latching mechanisms to accomplish the securing of carriage  140  in the correct position for imaging of test strips  134 . Once carriage  124  is fully extended, clamp assembly  150  can be removed from the system by the user and strips  134  are unclamped by squeezing lever  151  towards base  153  and then the user may dispose of the used test strips  134 . 
       FIG.  7    is a front view of the microcontroller circuit board  40  which is built around an ARM™ general purpose 32 bit surface-mount microcontroller  402  and a lensed mini-camera module  80  mounted on one side, along with a 3.6V power supply and all associated componentry. The CMOS camera  80  may, for example, be a two-megapixel color image sensor with 10× magnification lens and built-in infrared filter (visible light only), a variety of which are commercially available (e.g., Arduino™). The microcontroller circuit board  40  includes reinforced corner holes for pylon suspension from the top ( FIG.  6   ). On light board  83  white LEDs  406  are mounted to provide illumination for camera  80 . Referring back to  FIG.  6    these white LEDs  406  shine downward from light board  83 , and through hemispherical diffuser lenses  87  attached to light board  83  for illumination of the sampling tray  140  there beneath. On the flipside of circuit board  40  there is at least one RGB LED mounted directly beneath the segments  52  of the indicator panel  50  ( FIG.  1   ) for selective illumination thereof in a desired color (red, green, blue or white). This allows color-coded/directional guidance to the operator. 
       FIG.  8    is a photograph of the composite image of four test strips taken by the camera  80  while seated in imaging beds  133  (shown at rows 1 and 3-5) and a permanent calibration pattern on calibration label  139  printed or laminated atop the top shroud  128  of the imaging enclosure  122  ( FIG.  2   ). The permanent calibration reference  139  includes both a color calibration reference  302  comprising a transverse array of calibrated color swatches for RGB calibration, plus a series of transverse greyscale color references  304  ranging from dark to light for brightness calibration. The combination of test strips  134  typically includes but is not limited to pads for Total Alkalinity (0, 40, 80, 120, 180, 240 ppm); Free Bromine (0, 2, 4, 6, 10, 20 ppm) or Free Chlorine (0, 1, 2, 3, 5, 10 ppm); Total Chlorine (1, 0.5, 1, 2, 5, 10 ppm); Cyanuric Acid (0, 40, 70, 100, 150, 300 ppm); Hardness (0, 100, 200, 400, 800 ppm); Salt (0, 1000, 2000, 3000, 4000, 5000 ppm), Iron (0, 0.3, 0.6, 1.0, 3.0, 5.0 ppm); Copper (0, 0.3, 0.6, 1.0, 3.0 ppm); Borate (0, 15, 30, 50, 75, 100) Phosphate (0, 500, 1000, 2000, 3000 ppb); and pH (6.4, 6.8, 7.2, 7.5, 7.8, 8.4). The strips are imaged sequentially according to a schedule of optimal exposure times ranging from 20-60 seconds after the strips are dipped in water sample  165 . All images include at least test strips  134  and calibration reference(s)  134  and all are outputted to a remote computer for registration and colorimetric analysis. From the outputted image frames, a remote software application is able to automatically verify strip position and orientation, index and identify each strip, divide each pad into a grid array of panels, compute the color for each pad  135 , apply calibrations and display/output the results for the value of each chemical analyte. The remote computer/server may also return treatment recommendations including recommended chemical levels and identification of the proper chemical products to purchase for attaining those levels. 
       FIG.  9    is a block diagram of the imaging and analysis process. At step  400  the software begins with registration: locating the test strips in the captured image; analyzing the image to determine which strips are present; indexing the positions of each strip; and assigning a unique ID to each imaged test strip and sub-ID for each pad. 
     At step  420  the software sub-divides each pad into a checkerboard array of sub-areas. Given a subdivided image the software performs an image analysis on each cell. 
     At step  425  a calibration module employs an averaging sequence across the subdivided cells to account for and calculates a mean value for the cell. The imaging process is inherently prone to pixel variance across each sample region and the averaging process smooths the variance. This mean is used as the sample value for that subcell. 
     At step  430  the software initiates a flatfield adjustment to account for lighting variations within a given picture. Flatfield adjustments for all subcell regions are calculated from white-only calibration regions of the calibration row. The flatfield adjustment assumes that these areas should be “white”, and compensates for any variation. 
     At step  440  the software initiates a Grayscale adjustment using the permanent greyscale calibration references  304  to account for variation in image-capture-hardware (RGB/gamma distribution/etc.), aging of ambient lighting, etc. 
     At step  450  the calibration module compares the sample image back to the calibration standards stored in the program for each analyte and decides which calibration value is the best match for the sample image. 
     Finally at step  460  the color values computed for each test pad  135  are uploaded and cataloged, and every correction that was applied is uploaded and cataloged by device in a test history for the device. The test history for the device is monitored over time to provide drift alerts of the color values of reference colors  302  and  304  to the user. 
       FIG.  10    is a graph of the 7-way pH color calibration curve of pH value versus pixel value for red, green and blue channels. 
       FIG.  11    is an example report of the details of the color values used to create the calibration curve in  FIG.  9   . 
       FIG.  14    is photograph depicting an exemplary loading fixture  138  for loading a plurality of test strips  134  into the clamp assembly  150  simultaneously. The loading fixture  138  is similar to test platform  140  and includes a plurality of test beds  142  for each test strip  134 . The test beds  142  are spaced equal to the jaws of clamp assembly  150  and are slightly shorter than the test strips  154 . This way, the parallel beds  142  hold the test strips  134  parallel in position with their distal ends protruding outward from the beds  142  ready to be clamped by clamp assembly  150 . Loading fixture  138  also includes a platform  144  leading to the test beds  142 , and a pair of raised rails  147  extending across the platform  144  toward test beds  142  for guiding clamp  150  there across. In use, as shown in the lower inset of  FIG.  14   , the loading fixture  138  holds a plurality of test strips  134  oriented such that clamp assembly  150  can be slid along platform  144  and clamp the protruding ends of test strip  134 , thus having all test strips  134  properly oriented for wetting with sample water  165  and placing onto carriage  124  for imaging once inserted into strip reader  2 . 
     It should now be apparent that the above-described multi-strip reader provides a platform for more efficient reading, indexing, calibrating, correcting and interpreting multiple test strips at a time. It makes it possible to load multiple test strips into an imaging station with minimal effort and yet maximum positional precision. 
     Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims.