Abstract:
Method for validating the accuracy of automated analyzers by performing an improved dual dye ratio method procedure that uses at least first and second dye solutions in combination with gravimetric measurement of selected test solutions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part application of co-pending U.S. patent application Ser. No. 13/439,861, filed on Apr. 5, 2012, which claims priority to Japanese Patent Application No. 2011-086354, filed on Apr. 8, 2011, the disclosures of which are herein incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     Automated analyzers, including clinical biochemistry analyzers and other laboratory devices, have been conventionally used for many years. For example, automated clinical biochemistry analyzers are used to perform clinical testing on blood samples. These devices are required to produce results that are validated, and they must be calibrated, i.e., re-validated, on a regular basis. 
     Such analyzers have been calibrated using “standards” that are composed of the chemical substances present in test serums. However, the problems of accuracy of the calibration can arise, especially in terms of determining absolute values. 
     A method for improving the accuracy of the calibration can be accomplished by determining the differences between large numbers of test results using standards performed independently through blind studies conducted by several groups. Although this technique can be used universally, it is still inadequate for use as a method for confirming accuracy, because it is burdensome and time consuming. 
     In recent years, the certified accuracy of verification systems and devices has been determined by using analysis results obtained with a standard as true values based on a theoretical system for establishing the authenticity of world standards, and then determining accuracy by using trueness with respect thereto as a requirement for certification, and it is effective to realize validation techniques that coincide with these certification requirements. 
     In contrast, a validation technique has been previously proposed that improves calibration accuracy by reducing the effect of evaporation by dispensing an amount of liquid targeted for automated analysis (for example, 1 μl to 1000 μl) as determined according to a standard validation method from a liquid targeted for testing, and validating based on a dye method. 
     Validation techniques using dye methods consist of placing a prescribed amount of a reference solution containing a first dye component that absorbs light of a first wavelength in an absorbance detection container, measuring the optical absorbance of that wavelength component, placing a detection solution containing a second dye component that absorbs light of a second wavelength in the reference solution, and then measuring the optical absorbance of that wavelength component. 
     Since a comparison of the optical absorbance of the reference solution and the optical absorbance of the detection solution measured in this manner yields a value corresponding to the amount of the detection liquid, the amount of the detection liquid can be validated based on the amount of the reference liquid (based on the specifications of international standard—ISO8655—part 7). 
     Validation accuracy can be established for the elements used to determine accuracy of blood analysis results obtained by this dye method by firstly validating the light path length of the cell used for optical analyses, secondly validating the accuracy of dispensing of reaction reagents, thirdly validating the dispensing accuracy of biological specimens (blood), and fourthly validating incubation-temperature accuracy of the reaction layer. 
     SUMMARY 
     The embodiments generally relate to methods for validating and/or calibrating with a high degree of accuracy automated analyzers having liquid dispensers. The present methods for validating the accuracy of automated analyzers are directed to performing an improved dual dye ratio method validation procedure that uses first dye solution and second dye solution in a target test liquid, measuring at the weight of the second dye solution, performing a first and second optical analysis on the target test liquid, and performing a computational analysis that determines any deviation between and among the first and second optical analyses and the weight measurement for the second dye solution. 
     In one embodiment of the present method includes the steps of designating as a validation target an automated analyzer that sequentially carries out automated analyses by dispensing an automated analysis target liquid into a plurality of optical analysis cells by an analysis target liquid filling unit and sequentially filling a first dye solution (having red and blue dyes) dispensed from a first liquid holding unit into the plurality of optical analysis cells by using the analysis target liquid filling unit. Then, dispensing a second dye solution (having blue dye only) from a second liquid holding unit by using a diluent dispensing pipetter, and weighing, on the basis of a gravimetric method, a total weight of the diluent dispensing pipetter with the second dye solution (having blue dye only) using a diluent weighing unit, and pipetting the second dye solution (having blue dye only) into the optical analysis cells filled with the first dye solution (having red and blue dyes). Measuring a target liquid in the optical analysis cells comprising the first and second dye solutions by an optical absorbance detection unit, based on a dual dye ratio method, in order to determine the amount of liquid of the first dye solution as a target liquid volume measurement result, weighing, based on the gravimetric method, the diluent dispensing pipetter after pipetting the second dye solution by a pipetter weighing unit, and transferring the target liquid from the optical analysis cells to a reference value measurement unit (e.g., microplate and reader) by using a transfer pipetter and measuring, based on the dual dye ratio method, to determine by a second optical absorbance detection unit the amount of the first dye solution as a reference liquid volume measurement result. Finally, validating the dispensing accuracy of the analysis target liquid dispensing unit of the automated analyzer by computing any deviation between and among the reference liquid volume measurement result and the target liquid volume measurement result and the measurement results of the pipetter weighing unit and the diluent weighing unit determined based on the gravimetric method. 
     In another embodiment of the present method includes the steps of designating as a validation target an automated analyzer that sequentially carries out automated analyses by dispensing an automated analysis target liquid into a plurality of optical analysis cells by a first and second analysis target liquid filling units, and sequentially filling a first dye solution (having red and blue dyes) into the plurality of optical analysis cells by dispensing from a first liquid holding unit by using the first analysis target liquid filling unit. Then, dispensing a second dye solution (having blue dye only) from a second liquid holding unit by using a diluent dispensing pipette, and weighing the diluent dispensing pipetter with the second dye solution using a diluent weighing unit, and pipetting the second dye solution into the optical analysis cells filled with the first dye solution (having red and blue dyes). In addition, placing a third dye solution (having blue dye only) into the optical analysis cells containing the first and second dye solutions, dispensed from a third liquid holding unit, using the second analysis target liquid filling unit. Measuring a target liquid in the optical analysis cells comprising the first, second and third dye solutions by an optical absorbance detection unit, based on a dye method, to determine an amount of the first dye solution as a target liquid volume measurement result, and weighing the diluent dispensing pipetter after pipetting the second dye solution by a pipetter weighing unit, and transferring the target liquid from the optical analysis cells to a reference value measurement unit (e.g., microplate and reader) by using a transfer pipetter and measuring, based on the dual dye ratio method, to determine by a second optical absorbance detection unit the amount of the first dye solution as a reference liquid volume measurement result. Finally, validating the dispensing accuracy of the analysis target liquid dispensing unit of the automated analyzer by computing any deviation between and among the reference liquid volume measurement result and the target liquid volume measurement result and the measurement results of the pipetter weighing unit and the diluent weighing unit determined based on the gravimetric method. 
     According to the present method, the accuracy of validation results for an automated analyzer can be improved by determining the amount of a validation target liquid based on measurement of the amount of a reference liquid with respect to the amount of the validation target liquid based on measurement of a target liquid by a dual dye ratio method using first and second traceable dye solutions, using a target value measurement result according to a gravimetric method. 
     These and other objects, along with advantages and features of the present disclosure herein disclosed, will become apparent through reference to the following description and the accompanying drawings. Furthermore, it is understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic system diagram showing an embodiment of the present method. 
         FIG. 2  is a typical absorbance curve results of the present method. 
         FIG. 3  is a schematic system diagram showing the configuration of the second optical absorbance detection unit and a reference value measurement microplate. 
         FIG. 4  is a typical graphical representation of the validation/calibration results of the present method. 
         FIG. 5  is a schematic system diagram showing a second embodiment of the present method. 
         FIG. 6  shows a simplified diagram of an automated analyzer. 
         FIGS. 7A-7B  show various embodiments of a validation method to verify the accuracy of the light path length of an optical analysis cell in an automated analyzer. 
         FIG. 8  shows an embodiment of a validation method to verify the accuracy of dispensed volume of a dispensing pipette under test in an automated analyzer. 
         FIG. 9  shows a schematic diagram illustrating another configuration of the second optical absorbance detection unit and an optical measurement microplate. 
         FIGS. 10A-10C  show an embodiment of a method to determine the actual dispensed volume of the dispensing pipette under test in a validation section. 
         FIG. 11  shows an embodiment of a validation method to verify the accuracy of dispensed volume of another dispensing pipette under test in an automated analyzer. 
     
    
    
     DESCRIPTION 
     A clinical biochemistry automated analyzer R 0 , which is the validation target of the automated analyzer validation device  1 , holds sample blood serving as an analysis target in sample cups  19  on a sample rack  16 , dispenses a small prescribed amount of the sample blood from each of the sample cups  19  with a dispensing tube  18  that rotates in the direction indicated by arrow c in a sample filling unit  17  that composes a first analysis target filling unit, and fills the sample blood into optical analysis cells  2 . 
     In addition, the clinical biochemistry automated analyzer R 0  holds a sample reagent, which develops a color by reacting with a serum component to be analyzed at normal temperature, in a reagent bottle  14  on a reagent rack  11 , dispenses a small prescribed amount of the reagent with a dispensing tube  13  that rotates in the direction indicated by arrow b in a reagent filling unit  12  that composes a second analysis target filling unit, and fills the reagent into the optical analysis cells  2 . 
     A plurality of the optical analysis cells  2  are sequentially arranged along a peripheral edge  3 A of a turntable  3  that rotates intermittently in the direction indicated by arrow a, and as a result thereof, when the dispensing tubes  18  and  13  of the sample filling unit  17  and the reagent filling unit  12  have rotated to a prescribed filling position, each of the optical analysis cells  2  is sequentially filled with the sample blood and the coloring reagent. 
     Thus, the clinical biochemistry automated analyzer R 0  serving as the validation target of the automated analyzer validation device  1  is able to automatically analyze sample blood dispensed from the plurality of sample cups  19 A based on a chemical component contained in the serum thereof reacting in the optical analysis cells  2 . 
     In  FIG. 1 , during a typical automated analysis operation, the automatic analyzer validation device  1  fills a dye solution having a first dye (red and blue) serving as the sample liquid  19 A into the sample cups  19  serving as liquid retention portions that hold the sample blood when validating the clinical biochemistry automated analyzer R 0  serving as the validation target. 
     As a result, the automated analyzer validation device  1  in the case of  FIG. 1  validates the amount dispensed by the sample dispensing unit  17 . 
     In the automated analyzer validation device  1 , when the turntable  3  of the clinical biochemistry automated analyzer R 0  has been rotated intermittently in the direction indicated by arrow a, the optical analysis cells  2  are sequentially positioned at a reagent filling position P1, a sample filling position P2, a diluent filling position P3 and a target measuring position P4. 
     When an optical analysis cell  2  has been positioned at the sample filling position P2, the automated analyzer validation device  1  dispenses a prescribed amount of the sample liquid  19 A from the plurality of sample cups  19  with the dispensing tube  18  of the sample filling unit  17  provided on the sample rack  16  and fills the sample liquid  19 A into the optical analysis cell  2 . 
     Incidentally, the amount dispensed by the sample filling unit  17  at this time is equal to the amount of sample blood dispensed when the clinical biochemistry automated analyzer R 0  performs automated analysis. 
     The sample filling unit  17  aspirates the sample liquid  19 A from the plurality of sample cups  19  arranged in a row on the sample rack  16 , and as indicated by arrow c, rotates the dispensing tube  18  from the position of the sample cups  19  to the sample filling position P2 and fills the aspirated sample liquid  19 A into the optical analysis cells  2  followed by returning the dispensing tube  18  to its original position of the sample cups  19 . 
     In the case of this embodiment, a first dye solution is used for the sample liquid  19 A that demonstrates the optical characteristic of absorbing an optical component having a wavelength of 520 nm and 730 nm due to a first red and blue dye. 
     This first dye solution is a dye solution that contains uncertainty with respect to the red dye solution defined in the previously mentioned international standard ISO8655-7, and is referred to as a “traceable first dye solution” since this characteristic can be made to be traceable to the above-mentioned standard in consideration of this “uncertainty”. 
     The automated analyzer validation device  1  is made to fill a diluent  23 A from the diluent dispensing pipetter  21  when the optical analysis cells  2  have been positioned at the diluent filling position P3. 
     Dispensing work performed by the diluent dispensing pipetter  21  is carried out manually by an analysis technician of the clinical biochemistry automated analyzer R 0 . 
     During this dispensing work, a dispensing technician operates the diluent dispensing pipetter  21  and first aspirates a prescribed amount of a diluent  23 A from a diluent bottle  23  serving as a liquid holding portion arranged on a diluent rack  22 . 
     In the case of this embodiment, a second dye solution is used for the diluent  23 A that demonstrates the optical characteristic of absorbing an optical component having a wavelength of 730 nm due to a second blue dye. 
     This second dye solution is a dye solution that contains uncertainty with respect to the blue dye solution defined in the previously mentioned international standard ISO8655-7, and is referred to as a “traceable second dye solution” since this characteristic can be made to be traceable to the above-mentioned standard in consideration of this “uncertainty”. 
     When an optical analysis cell  2  has reached the target measuring position P4 as a result of rotation of the turntable  3 , the automated analyzer validation device  1  detects the optical absorbance of a measurement target liquid  26  contained in the optical analysis cell  2  with an optical absorbance detection unit  25 , and transmits an optical absorbance detection signal S 1  to a target measurement result processing unit  27  having the configuration of a microcomputer. 
     In this embodiment, the optical absorbance detection unit  25  comprises a detecting light L1 emitted from a white light source  25 A being passed through the optical analysis cell  2 , the optical absorbance detection unit  25  extracts a light component of a prescribed measurement wavelength range with a filter  25 B and allows the light to enter a photoelectric converter  25 C. 
     As a result, the detecting light L1 enters the filter  25 B after the optical component of a wavelength corresponding to the optical absorbance characteristics of the dye present in a measurement target liquid  26  has been absorbed as a result of passing through the measurement target liquid  26 . 
     In this embodiment, the measurement target liquid  26  contains a 520 nm and 730 nm wavelength components possessed by the red and blue dye solution  19 A filled into the optical analysis cells  2  at the sample filling position P2, and a 730 nm wavelength component possessed by the blue dye solution  23 A filled at the diluent filling position P3. 
     Thus, the wavelength components of the measurement target liquid  26  in the optical analysis cells  2  at the target measuring position P4 are absorbed in accordance with the optical absorbance curve K1 shown in  FIG. 2  for the 520 nm and 730 nm wavelength components. 
     As a result, in the optical absorbance detection unit  25 , by calculating the following by the target measurement result processing unit  27  based on the ratio of the optical absorbance of the two wavelength components: 
     
       
         
           
             
               
                 
                   
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                             A 
                             S 
                           
                           
                             A 
                             B 
                           
                         
                         
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             V S =volume of red dye solution 
             V B =volume of blue dye solution 
             A S =optical absorbance of red dye solution (520 nm) 
             A B =optical absorbance of blue dye solution (730 nm) 
             K=correction value determined at time of shipment from factory the dispensed amount of the sample liquid  19 A in the form of the red dye solution can be determined based on the dispensed amount of the diluent  23 A and sample liquid  19 A in the form of the blue dye solution. 
           
         
       
    
     Here, formula (1) is specified as a liquid volume measurement method, based on the dye method according to international standard ISO8655-7, and indicates that the amount of the sample liquid  19 A dispensed by the dispensing tube  18 , namely the volume V S  of the sample liquid  19 A, can be determined as a value obtained by multiplying the ratio of the optical absorbance A S  of the sample liquid  19 A in the form of the red dye solution to the optical absorbance A B  (blue dye) of the diluent  23 A and sample liquid  19 A by the dispensed amount of the diluent in the form of the blue dye solution by the diluent dispensing pipetter  21 , namely the volume V B  of the diluent  23 A and sample liquid  19 A. Formula (1) above is a basic formula to facilitate understanding of the dual dye ratio method. Details regarding calibration of amount dispensed by the dispensing tube will be described by modified formulas or equations as describedbelow herein. These modified formulas theoretically relate to formula (1) above. 
     In addition, since the ratio of the optical absorbance A S  of the sample liquid  19 A in the form of the red dye solution to the optical absorbance A B  of the diluent  23 A and sample liquid  19 A in the form of the blue dye solution represents the degree of dilution of the sample liquid  19 A in the form of the red dye solution relative to the diluent  23 A and sample liquid  19 A in the form of the blue dye solution, this indicates that the injection volume V S  of the sample liquid  19 A can be determined as the ratio of the injection volume of the sample liquid  19 A to the volume of the diluent  23 A and sample liquid  19 A contained in the optical analysis cells  2 . 
     In this manner, the optical absorbance detection unit  25  and the target measurement result processing unit  27  compose a target liquid volume measurement unit for the measurement target liquid  26  in the optical analysis cells  2  at the target measuring position P4. 
     As indicated by arrow d, the entire volume of the measurement target liquid  26  filled into the optical analysis cells  2  at the target measuring position P4 is removed as a measurement target transfer liquid  26 A by a dispensing technician using the transfer pipetter  30 , and transferred to a reference value measurement microplate  32  on a reference value rack  31 . 
     The entire volume of the measurement target liquid  26  is aspirated from the optical analysis cells  2  with the transfer pipetter  30  during manual work performed by a dispensing technician in the same manner as previously described with respect to the diluent dispensing pipetter  21 , and the measurement target liquid  26  is transferred to one of a plurality of retention wells  33  provided in the reference value measurement microplate  32 . 
     In addition to having the configuration previously described, the validation device  1  is provided with a balance  40 A that composes the diluent weighing unit  40  on the diluent rack  22 . 
     The balance  40 A of the diluent weighing unit  40  weighs the total weight of the diluent dispensing pipetter  21  and the diluent  23 A contained therein as a result of a dispensing technician dispensing the diluent  23 A from the diluent bottle  23  using the diluent dispensing pipetter  21 , and placing on the balance  40 A that composes the diluent weighing unit  40 . 
     In addition to recording the result W1 of weighing in the diluent weighing unit  40 , the dispensing technician fills the diluent  23 A by transporting the diluent dispensing pipetter  21  retaining the dispensing liquid  23 A to the optical analysis cells  2  at the diluent filling position P3. 
     Following this dispensing work, an operator executing diluent operation places the diluent dispensing pipetter  21  that has currently been used on a balance  46 A that composes the pipetter weighing unit  46  provided on a pipetter rack  45  for a weight result W2. It is within the scope of the present method to use weighing unit  46  to obtain this weight measurement for the empty pipette  21 . 
     At this time, the pipetter weighing unit  46  determines the weight of the diluent dispensing pipetter  21  after having emptied the diluent  23 A into optical analysis cell  2 , and the dispensing technician records the result of that weighing. 
     In this manner, the weight of the diluent  23 A filled into the optical analysis cells  2  by the dispensing technician at the diluent filling position P3, and thus the amount of the diluent  23 A dispensed by the diluent dispensing pipetter  21 , can be determined by a gravimetric method by comparing the weighing result obtained from the diluent weighing unit  40  and the weighing result obtained from the pipetter weighing unit  46 . 
     As shown in  FIG. 3 , a second optical absorbance detection unit  41  is used to measure the amount of the measurement target transfer liquid  26 A placed in the retention wells  33  of the reference value measurement microplate  32  using a dye method as a highly accurate reference value. The total volume of the measurement target transfer liquid  26 A will be calculated by the equations presented as described below herein. 
     The optical absorbance detection unit  41  has a white light source  41 A that emits a white light L2, and causes the white light L2 to enter a photoelectric converter  41 C with respect to a filter  41 B after having passed through the measurement target transfer liquid  26 A. 
     Here, as was previously described with respect to  FIG. 2 , the measurement target transfer liquid  26 A has optical absorbance characteristics such that a blue dye component of a wavelength of 730 nm of the diluent  23  and sample liquid  19 A and a red dye component of a wavelength of 520 nm of the sample liquid  19 A are absorbed as represented by the optical absorbance curve K1, and the filter  41 B extracts light of a wavelength range that includes these dye components followed by the light entering the photoelectric converter  41 C. 
     The photoelectric converter  41 C is configured so as to arithmetically process the above-mentioned formula (1) at high accuracy, including uncertainty (thus, making it traceable), based on the specifications of the previously described international standard ISO8655-7, and as a result, an optical absorbance detection signal S 2  obtained from the photoelectric converter  41 C is transmitted to a reference measurement result processing unit  44  having the configuration of a microcomputer as a reference value representing the volume of the sample liquid  19 A contained in the measurement target transfer liquid  26 A at a high level of accuracy that is close to that of the measurement result obtained with a standard equivalent to the device of the aforementioned international standard. 
     In this manner, the reference measurement result processing unit  44  retains the measurement result of the volume of the sample liquid  19 A contained in the measurement target transfer liquid  26 A with high accuracy as a reference value. 
     The optical absorbance detection unit  41  determines measured values for reference values in this manner for the measurement target transfer liquid  26 A retained in all of the retention wells  33  of the reference value measurement microplate  32 , and accumulates those measured values in the reference measurement result processing unit  44 . 
     The reference value measurement result accumulated in the reference measurement result processing unit  44  of the reference value judgment unit  32  is transmitted to the dispensing accuracy judgment unit  47 A of the validation result processing unit  47  as a reference liquid volume signal S 21 . 
     The dispensing accuracy judgment unit  47 A determines the reference liquid volume signal S 21  obtained from the reference value measurement result processing unit  44 , and validation result processing unit  47  confirms the amount dispensed by the diluent dispensing pipetter  21  using a gravimetric method based on the weighing results W1 and W2 of the diluent weighing unit  40  and the pipetter weighing unit  46 , respectively, as a validation result that expresses the measuring limit (uncertainty) of the clinical biochemistry automated analyzer R 0  serving as the validation target. 
     It is within the scope of the present method to have the target measurement result processing unit  27 , the reference value measurement result processing unit  44  and the validation result processing unit  47  be a single microprocessor or computer or be distributed as shown. 
     As shown in  FIG. 4 , in addition to plotting a coefficient of variation K1 within the range of 0% to 3.0% on the horizontal axis, by further plotting a degree of accuracy K2 within the range of −0.03 to +0.03 on the vertical axis, this validation result can be expressed according to whether or not the dispensing accuracy for the amount of the sample liquid  19 A dispensed from the sample cups  19  by the sample filling unit  17  lies within a dispensing accuracy curve DT. 
     Here, the coefficient of variation K1 represents the degree of variation of the validation result, while the degree of accuracy K2 is equal to 0 when the validated dispensing amount is the true value, and the degree of variation from the true value K2=0 is represented as K2+0.01, +0.02 . . . or −0.01, −0.02 . . . . 
     In this manner, when a validation result is within an area demarcated by the dispensing accuracy curve DT that passes through a target coefficient of variation K1=0 to K=10 and a target degree of accuracy K2=+K20 to −K20, the dispensing accuracy of the automated analyzer serving as the validation target is validated to be within the allowed range. 
     The method provides an automated analyzer R 0  is the validation target that sequentially carries out automated analyses by dispensing an automated analysis target liquid  19 A into a plurality of optical analysis cells  2  by way of sample filling unit  17 . A first dye solution  19 A is sequentially filled into the plurality of optical analysis cells  2  dispensing from a first liquid holding unit  19 , and together with dispensing a second dye solution  23 A from a second liquid holding unit  23  through the use of a diluent dispensing pipetter  21 . The total weight of the diluent dispensing pipetter  21  in the dispensing state, i.e., with the dye solution, is obtained, based on a gravimetric method, using a diluent weighing unit  40 . The second dye solution  23 A is dispensed into the optical analysis cells  2  which is already filled with the first dye solution  19 A. 
     Thereafter, determining the amounts of liquid in the optical analysis cells  2  filled with the first and second dye solutions  19 A and  23 A by using an optical absorbance detection unit  25  to determine a light path length of optical analysis cells  2  with the equation presented as described beow herein, weighing the emptied diluent dispensing pipetter  21  (after having been filled with the second dye solution  23 A) using a pipetter weighing unit  46 , based on a gravimetric method. Transferring the contents of the optical analysis cells  2  filled with the first and second dye solutions  19 A and  23 A to a reference value measurement microplate  32  using a transfer pipetter  30  and measuring (based on a dual dye ratio method) using a second optical absorbance detection unit  41  to obtain a reference measured value. Performing a computational analysis using all of the measured results obtained by the present method to validate the dispensing accuracy of the sample filling unit  17  of the automated analyzer R 0  by determining any deviation between and among the reference measured value and the target measured value determined based on a dye method and the deviation between measurement results of the pipetter weighing unit  46  and the diluent weighing unit  40  determined based on a gravimetric method. 
     In  FIG. 5 , another embodiment of the present method, the same reference symbols are used to indicate those elements and features corresponding to  FIG. 1 . 
     The automated analyzer validation device  1 X of  FIG. 5  differs from the automated analyzer validation device  1  of  FIG. 1  in that, in contrast to the automated analyzer validation device  1  of  FIG. 1  (directed to determining the dispensed amount of the sample liquid  19 A that is a red dye solution based on the dispensed amount of the diluent  23 A that is blue dye solution using a dye method), the validation device  1 X of  FIG. 5  determines the dispensed amount of a reagent solution  14 A that is a red and blue dye solution based on the dispensed amount of the diluent  23 A and the sample liquid  19 B that are blue dye solutions. 
     Namely, in the case of  FIG. 5 , the reagent solution  14 A dispensed from the reagent bottle  14  is filled into optical analysis cells  2  on the turntable  3  by a reagent filling unit  12  at a reagent filling position P11. 
     In this case, a first dye solution demonstrating the optical characteristic of absorbing an optical component having a wavelength of 520 nm and 730 nm due to the first red and blue dye is used for the reagent solution  14 A. 
     Continuing, the diluent  23 A manually dispensed from the diluent bottle  23  by a dispensing technician is filled into the optical analysis cells  2  by the diluent dispensing pipetter  21  at a diluent filling position P12. 
     In this case, a second dye solution demonstrating the optical characteristic of absorbing an optical component having a wavelength of 730 nm due to the second blue dye is used for the diluent  23 A. 
     Here, prior to filling the diluent  23 A at the diluent filling position P12, the diluent dispensing pipetter  21  in the state of having dispensed the diluent  23 A is placed on the balance  40 A that composes the diluent weighing unit  40  and the total weight thereof is weighed. 
     After having filled the diluent  23 A, the diluent dispensing pipetter  21  is placed on the balance  46 A that composes the pipetter weighing unit  46  and the weight of the pipetter  21  is weighed. 
     Continuing, the sample liquid  19 B dispensed from the sample cups  19  by the sample filling unit  17  is filled into the optical analysis cells  2  at a sample filling position P13. 
     In this case, a third dye solution demonstrating the optical characteristic of absorbing optical components having a wavelength of 730 nm due to the second blue dye in the same manner as the above-mentioned diluent  23 A is used for the sample liquid  19 B. 
     Continuing, the optical absorbance of the measurement target liquid  26  in the optical analysis cells  2  is detected by the optical absorbance detection unit  25  at a measurement target position P14. 
     Accompanying this, the entire volume of liquid filled into the optical analysis cells  2  is transferred to a reference value measurement microplate  32  by the transfer pipetter  30  at the target measuring position P14 as indicated by arrow d. 
     In the configuration of  FIG. 5 , when an optical analysis cell  2  has been brought to the reagent filling position P11 by the turntable  3 , the validation device  1 X dispenses a first dye solution in the form of the reagent solution  14 A from the reagent bottle  14  with the dispensing tube  13  of the reagent filling unit  12  and fills the optical analysis cell  2 . 
     Continuing, after the second dye solution in the form of the diluent dispensed by the diluent dispensing pipetter  21  from the diluent bottle  23  by a dispensing technician has been filled into the optical analysis cells  2  filled with the reagent solution  23 A at the diluent filling position P12, the detection device  1 X fills the third dye solution in the form of the sample liquid dispensed from the sample cups  19  by the sample filling unit  17  into the optical analysis cells  2  at the sample filling position P13. 
     In this manner, as a result of the first dye solution of the first red and blue dye filled at the reagent filling position P11, the second dye solution of the second blue dye filled from the diluent dispensing pipetter  21  at the diluent filling position P12, and the third dye solution of the second blue dye filled by the sample filling unit  17  at the sample filling position P13 being mixed in the optical analysis cells  2 , the optical absorbance detection unit  25  detects optical absorbance at the measurement target position P14 by using this mixture as the measurement target liquid  26 . 
     At this time, the optical absorbance detection unit  25  determines the volume of the red and blue reagent solution  14 A serving as the first dye based on the ratio between the optical absorbance of the reagent solution  14 A serving as the red wavelength component of the first dye and the optical absorbance of the diluent solution  23 A and the sample liquid  19 B serving as blue wavelength components of the second dye in accordance with the above-mentioned formula (1) using a dye method based on the specifications of ISO8655-7, and accumulates that volume in the target measurement result processing unit  27 . 
     Here, in conjunction with the liquid volume of the second dye (blue), although error occurs in the liquid volume of the first dye (red and blue) in the above-mentioned formula (1) due to the sample liquid  19 B having been filled into the diluent  23 A, if the amount of the diluent  23 A (namely, the second dye solution) that composes the liquid volume of the second dye (blue) is known and the amount of the sample liquid  19 B (namely, the third dye solution) is known, then the amount of the reagent solution  14 A of the first dye (namely, the first dye solution) can be determined with high accuracy with almost no effect of evaporation in the dye method. 
     When this is done, in the case of  FIG. 5  as well, in addition to weighing the total weight, including the diluent  23 A dispensed from the diluent bottle  23  by the diluent dispensing pipetter  21  in the diluent weighing unit  40 , a dispensing technician also weighs the weight of the diluent dispensing pipetter  21  after having filled the diluent  23 A at the diluent filling position P12 in the pipetter weighing unit  46 . 
     In this manner, the amount of the diluent  23 A dispensed by the diluent dispensing pipetter  21  can be confirmed by a gravimetric method according to the difference between the weighing result of the diluent weighing unit  40  and the weighing result of the pipetter weighing unit  46 . 
     In addition, the dispensed amount of the measurement target transfer liquid  26 A transferred to the retaining wells  33  of the reference value measurement microplate  32  by the transfer pipetter  30  is determined as a highly accurate reference value corresponding to a standard based on the dye method by the reference value measurement microplate  32  of  FIG. 3 . 
     This reference value judgment result represents the dispensed amount of the red component contained in the measurement target transfer liquid  26 A transferred by the transfer pipetter  30 , namely the dispensed amount of the reagent solution  14 A of the first dye solution dispensed from the reagent bottle  14  by the reagent filling unit  12 , and this is accumulated in the reference value judgment result processing unit  44  of the reference value measurement microplate  32 . 
     In this manner, the validation result processing unit  47  of the reference value measurement microplate  32  is able to determine a dispensing accuracy curve DT as previously described with respect to  FIG. 4  and the reference liquid volume signal S 21  obtained from the reference value measurement result processing unit  44 . 
     As a result, the validation device  1 X of  FIG. 5  is able to validate the dispensing accuracy of the reagent filling unit  12  of the clinical biochemistry automated analyzer R 0  serving as the validation target based on the resulting dispensing accuracy curve DT. 
     In this manner, the liquid volume of the blue dye component can be measured according to the equations presented as described below herein and this can be confirmed as the liquid volume V B  of the blue dye liquid in the arithmetic processing of the aforementioned formula (1) based on a dye method, thereby making it possible to even more reliably confirm certainty with respect to results of measuring the dispensed amount of the red component. 
     Incidentally, if the amount of the reagent solution  14 A dispensed by the reagent filling unit  12  is determined according to a dye method using the configuration shown in  FIG. 5  after having determined the amount of the sample liquid  19 B dispensed by the sample filling unit  17  according to a dye method using the validation device  1  having the configuration shown in  FIG. 1 , validation of the dispensed amount of the sample filling unit  17  used to dispense blood and validation of the dispensed amount of the reagent filling unit  12  used to dispense a coloring reagent, which are both important elements of analysis results in the clinical biochemistry automated analyzer R 0 , can be carried out with high accuracy. 
     The method of  FIG. 5  provides an automated analyzer R 0  is the validation target that sequentially carries out automated analyses by respectively dispensing an automated analysis target liquid  14 A into a plurality of optical analysis cells  2  by first and second analysis target liquid filling units  12  and  17 . A first dye solution  14 A is sequentially filled into the plurality of optical analysis cells  2  by dispensing from a first liquid holding unit  14  by using the first analysis target liquid filling unit  12 , and together with dispensing a second dye solution  23 A from a second liquid holding unit  23  using a diluent dispensing pipetter  21 , the total weight of the diluent dispensing pipetter  21  with the second dye solution  23 A is weighed by a diluent weighting unit  40 , based on a gravimetric method. A third dye solution  19 B, which the same dye as the second dye solution  23 A, is dispensed into the optical analysis cells  2  filled with the first and second dye solutions  14 A and  23 A from a sample cup  19  by using the sample filling unit  17 . 
     Measuring the amounts of liquid in the optical analysis cells  2  filled with the first, second and third dye solutions, i.e.,  14 A,  23 A and  19 B, respectively, by an optical absorbance detection unit  25  in order to determine the light path length of optical analysis cells  2  as a target value measurement result. Obtaining the weight of the diluent dispensing pipetter  21  after having been filled with the second dye solution  23 A by a pipetter weighing unit  46  based on a gravimetric method. 
     Transferring the entire content from the optical analysis cells  2  filled with the first, second and third dye solutions, i.e.,  14 A,  23 A and  19 B, respectively, to a reference value measurement microplate  32  by using a transfer pipetter  30 . Based on a dual dye ratio method, using a second optical absorbance detection unit to determine the amount of the first dye solution  14 A as a reference value measurement result. Performing a computational analysis to validate the dispensing accuracy of the analysis target liquid filling unit  12  of the automated analyzer R 0 , according to any deviation between and among the reference value measurement result and the target value measurement result, determined based on a dual dye ratio method, and the measurement results of the pipetter weighing unit  46  and the diluent weighing unit  40  determined to prove that almost no residual amount of transfer volume based on a gravimetric method. 
     Although the above-mentioned embodiments described in the present disclosure refer to a clinical biochemistry automated analyzer used for haematological testing, the present disclosure is not limited thereto, but rather can also be applied to a wide range of other clinical biochemistry automated analyzers. 
     It is also within the scope of the present disclosure to have the manual pipetting of the dye solutions and target liquids performed by a robotic handling device or automated dispensing units to have a fully automated process. In addition, the weighing of the pipette may be performed on a single weighing unit. 
       FIG. 6  shows a simplified diagram of an automated analyzer  600 . The automated analyzer  600  is similar to the automated analyzer R 0  as described in  FIG. 1 . As such, common features or elements may not be described or described in detail. 
     The automated analyzer  600 , for example, includes a sample section  650 , a reagent section  655 , a dilution section  660 , a reaction section  665  and an analysis section  670 . The automated analyzer may also include other suitable sections. 
     The sample section  650  has a sample rack or sample table  616  and a drive unit (not shown) for rotating the sample table. The sample table includes a plurality of holes on the periphery thereof to hold a plurality of sample cups  619 . The sample cups are filled with sample solution  619 A. The sample solution includes one or more components to be analysed. These sample cups are to be transferred to a suction position SC1 by rotation of the sample table as required. The sample section includes a rotatable sample dispensing unit  617  having an arm for holding an automated sample dispensing tube or pipette  618 . The sample dispensing unit includes a drive unit which enables the sample dispensing pipette to move and rotate between the suction position to a discharge position DC1 in a direction indicated by arrow c. 
     The reagent section  655  includes similar configuration as the sample section. As shown, the reagent section has a reagent rack or reagent table  611  and a drive unit (not shown) for rotating the reagent table. The reagent table holds a reagent bottle  614 . Although one reagent bottle is shown, it is understood that there could be more than one reagent bottle. The reagent bottle is filled with a reagent solution  614 A which develops a color by reacting with a component of the sample solution to be analysed. The reagent bottle is to be transferred to a suction position SC2 by rotation of the reagent table as required. The reagent section also includes a rotatable reagent dispensing unit  612  having an arm for holding an automated reagent dispensing tube or pipette  613 . The reagent dispensing unit includes a drive unit which enables the reagent dispensing tube to move and rotate between the suction position to a discharge position DC2 in a direction indicated by arrow b. 
     The reaction section  665  includes a reaction turntable  603  and a drive unit (not shown) for rotating the reaction turntable. The reaction turntable has a plurality of holes for holding a plurality of optical analysis cells  602 . The optical analysis cells, for example, are of rectangular shape and are transparent. The optical analysis cells, for example, may be made of moulded plastics or glass. The optical analysis cell may be made of other suitable materials or in other suitable shapes as long as it allows for optical or photometric measurement to be performed. The plurality of optical analysis cells are sequentially arranged along a peripheral edge  603 A of the turntable that rotates intermittently in a counter clockwise direction indicated by arrow a. It is understood that the turntable may also rotate in a clockwise direction. The reaction section also includes a light source  625 A. 
     The diluent section  660  includes a diluent rack or table  622 . The diluent table holds a diluent bottle  623 . Although one diluent bottle is shown, it is understood that there could be more than one diluent bottle. The diluent bottle is filled with a diluent solution  623 A which dilutes the sample solution. The diluent section includes a diluent dispensing pipette  621 . The diluent dispensing pipette may be moved between a suction position SC3 at the diluent table and a discharge position DC3 at the reaction turntable. Although the diluent dispensing pipette is shown as a manual dispensing pipette, it is understood that the diluent section may include an automated diluent dispensing unit having a rotatable arm which holds the diluent dispensing pipette. 
     The analysis section  670  includes an optical absorbance detection unit  625 . The optical absorbance detection unit, for example, is a photometer. The analysis section includes a filter  625 B which allows the photometer to extract a light component of a prescribed measurement wavelength range. The analysis section also includes a photoelectric converter  625 C for converting a measurement signal according to the intensity of the transmitted light into a digital signal. The analysis section includes a processing unit  627  having at least a microcomputer and a display unit. The microcomputer controls the operation of the sample, reagent and reaction sections. The display unit displays the conditions of analysis, such as dispensing volumes of the sample solution, reagent solution and dilution solution as well as the absorption measurement results obtained from the photometer for analysis of the component of the sample solution. 
     The automated analyzer  600  may be used to perform clinical analysis of particular components of a sample quickly and with minimal operator requirement. For example, the automated analyzer may be used to assess or calculate the amount of a particular component within a sample. For instance, during normal operation of the automated analyzer, the sample cups of the sample section are used to hold sample solution  619 A, such as blood or serum. In such case, the automated analyzer, for example, may be used to analyze or calculate the amount of a component within the blood or serum samples, such as albumin, sugar, enzyme, etc. For simplicity and for illustration purpose, serum will be used as an example of the sample solution while albumin will used as an example for the component for analysis for describing the normal operation of the automated analyzer. It is understood that other components of blood or serum may serve as the component for analysis. 
     A normal operation of the automated analyzer  600  will now be described. A user defines a small prescribed amount of serum and a small prescribed amount of reagent through an input device which is coupled to the microcomputer. The start button of the analyzer is depressed to initiate the analysis process. When a sample cup  619 A containing the serum reaches a suction position SC1 by rotation of the sample table  616 , the sample dispensing pipette  618  sucks and holds the small prescribed amount of the serum at the suction position on the sample table. The sample dispensing unit then rotates the filled sample dispensing pipette in the direction indicated by arrow c from the suction position to a discharge position. For example, when the sample dispensing pipette reaches the discharge position DC1, such as the specimen input position, it discharges the prescribed amount of serum defined by the user into an empty optical analysis cell  602  at the discharge position on the turntable  603 . 
     The process may continue by rotating the optical analysis cell which is filled with serum to a reagent discharge position. For example, when the optical analysis cell which is filled with serum reaches the reagent discharge position, the reagent dispensing pipette  613  sucks and holds the small prescribed amount of reagent defined by the user at the suction position SC2 on the reagent table  611 . The reagent, for example, may be any suitable chemical substance which develops a color by reacting with albumin of the serum. For example, the reagent solution may be bromocresol-green dye which develops a blue-green color when reacting with albumin. The reagent dispensing unit then rotates the filled reagent dispensing pipette in the direction indicated by arrow b from the suction position to the discharge position DC2. For example, when the reagent dispensing pipette reaches the reagent discharge position, it discharges the prescribed amount of bromocresol-green dye into the optical analysis cell which is filled with serum at the discharge position, such as DC2, on the turntable  603 . 
     As described, the analysis process started with the dispensing of the sample solution into an empty optical analysis cell followed by the dispensing of the reagent solution. Alternatively, the analysis process may initiate with dispensing of the reagent solution into an empty optical analysis cell, followed by dispensing of the sample solution into the optical analysis cell filled with reagent. In such case, when the reagent dispensing pipette reaches a reagent discharge position, it discharges the reagent into an empty optical analysis cell. The optical analysis cell which is filled with reagent is rotated to the sample discharge position. The prescribed amount of sample solution is then discharged into the optical analysis cell filled with reagent. 
     The process continues to rotate the filled optical analysis cell to a diluent discharge position. For example, when the filled optical analysis cell reaches the diluent discharge position DC3, such as the diluent filling position, a prescribed amount of a diluent, such as saline, is dispensed into the optical analysis cell which is filled with serum and bromocresol-green dye. For example, the user manually aspirates a prescribed amount of saline from a diluent bottle  623  using a diluent dispensing pipette  621  and transfers the saline to the filled optical analysis cell at the diluent discharge position. Once the diluent is discharged into the filled optical analysis cell, the sample solution, reagent and diluent are mixed by a mixing mechanism (not shown), such as an agitator, to form a measurement target liquid  626 . 
     The optical analysis cell filled with the measurement target liquid  626  is rotated to a measuring position M64, such as the target measuring position. The measurement target liquid traverses the light from the light source  625 A so that the colored condition of the measurement target liquid is observed. Thus, an optical characteristic of the measurement target liquid can be measured several times. 
     The light L61 from the light source  625 A passes through the optical analysis cell which is filled with the measurement target liquid in a horizontal direction. The transmitted light traverses a filter  625 B which allows the photometer to extract a light component of a prescribed measurement wavelength range. The filter  625 B, for example, may be a 630 nm filter. Other suitable filter may also be used, depending on the dye component of the reagent solution. A signal having a magnitude representative of a transmitted light intensity is supplied to the converter  625 C. The analog signal is then converted to a digital signal by the converter and the digital signal is fed to the microcomputer through the interface where necessary operations are carried out and the operation results are stored in a memory. After several times of optical or photometric measurements for the measurement target liquid have been completed, the data obtained in the several times of measurements are compared and processed as required, and a concentration value of the component of analysis is calculated. The analysis process which calculates the concentration value of the component of analysis is displayed at the display unit. 
     The analysis process performed by an automated analyzer, for example, is to calculate the concentration value of the albumin contained in the serum. As described, during normal operation of the automated analyzer, the bromocresol-green dye reacts with albumin and develops a color, such as blue-green color. Therefore, the concentration of albumin within the serum is the same as the concentration of the bromocresol-green dye or color component of the reagent solution which binds with albumin. 
     The concentration of the dye component in the optical analysis cell, such as the concentration of the bromocresol-green dye which binds the albumin, is determined via photometric method based on the Beer-Lambert law. This law states that when light passes through a solution containing some concentration of dye or color component, there is a linear relationship between the concentration of the dye component and the amount of energy it absorbs. The Beer-Lambert equation is presented as follows:
 
A λ =ε λ LC  (2)
 
where
         A λ =absorbance of the dye component at a specific wavelength λ,   ε 80 =molar absorptivity, which is a measure of the amount of light absorbed per unit concentration,   L=path length of the light that passes through the optical analysis cell in which the solution containing some concentration of dye or color component is contained, and   C=concentration of the dye component in the optical analysis cell.       

     As shown, equation (2) above illustrates that absorbance (A λ ) is directly proportional to the other parameters. Thus, this proportionality is used in an automated analyzer to determine the unknown concentration of the dye component in a solution with the condition that the molar absorptivity of particular dye component at the measurement wavelength and the path length of the light through the solution are known or fixed. 
     Equation (2) above can be rearranged to calculate, for example, the concentration value of the albumin within the serum. When light L61 passes through the colored measurement target solution  626 , the intensity of the transmitted light decreases exponentially with the increase in concentration of the absorbing bromocresol-green dye. The amount of the light energy absorbed depends on the number of bromocresol-green dye molecules which react with albumin and the thickness of the measurement target liquid, which is the path length of the light. As such, intensity of light energy leaving the measurement target solution is used to provide the absorbance value of the dye component at 630 nm. Since the absorbance value is obtained from measurement of the intensity of the transmitted light while the molar absorptivity of the dye and the light path length are constant and known, the concentration of the dye which is equivalent to the concentration of albumin can be obtained. 
     The analysis process to calculate the amount of albumin within the serum in the optical analysis cell is completed. The analysis process may continue with calculation of albumin in subsequent or adjacent optical analysis cell in the automated analyzer. 
     In the example given above, serum serves as the sample solution, albumin serves as the component of analysis, bromocresol-green dye serves as the reagent solution while saline serves as the diluent. It is understood that other suitable sample solution, component analysis, reagent and diluent solutions may also be useful. 
     The concentration value of the component of analysis within a sample solution as calculated above is based on the assumption that the various elements of the automated analyzer are operated at precise and accurate conditions. However, I have discovered that this is not always the case and thus the calculated value of the component of analysis in a sample solution by the automated analyzer may not be reliable. For example, I have found that the path length of each optical analysis cells may deviate from the path length dimension provided by the manufacturer of the optical analysis cell. Further, the path length of the optical analysis cell may not be fixed or constant as these optical analysis cells may be replaced with new optical analysis cells after numerous times of usage or certain time period. In addition, wash solution or system solution may be introduced to wash the dispensing pipette after a dispensing operation is performed. However, there may be some residual wash solution which remains in the dispensing pipette. The residual wash solution remaining in the dispensing pipette may cause the actual dispensed volume of the sample dispensing pipette or the reagent dispensing pipette to be below the volume as prescribed or defined by the user. Therefore, to determine whether the automated analyzer is operating in precise and accurate conditions such that the results obtained from the automated analyzer is reliable, it is necessary to verify or validate the accuracy of the light path length of the optical analysis cell and the accuracy of the dispensing volume of the dispensing pipettes of the automated analyzer. Validation of the results obtained from automated analyzer is also necessary to fulfil national or regional compliance. 
     As described above, the path length of the optical analysis cell may not be fixed or constant. In view of this, the concentration of component of analysis as obtained from the automated analyzer which is calculated based on equation (2) above may not be reliable. A validation method to determine or verify the accuracy of light path length of an optical analysis cell used in an automated analyzer will now be described.  FIG. 7A  shows an embodiment of a validation method  700  to determine or verify the accuracy of the light path length (L O ) of an optical analysis cell used in an automated analyzer. As shown in  FIG. 7A , the automated analyzer includes the same elements as that described in  FIG. 6 . For example, the automated analyzer includes a sample section  650 , a reagent section  655 , a reaction section  665  and an analysis section  670 . As such, common features and features having the same reference numerals in  FIG. 6  will not be described in detail. 
     In one embodiment, to determine the accuracy of the light path length of an optical analysis cell, the reagent bottle  614  is provided with a test solution  714 A. The test solution  714 A, for example, is a dye solution containing known molar absorptivity and concentration of a dye component. For example, the test solution  714 A is a blue dye solution having absorbance maxima at 730 nm with known error (uncertainty) traceable to National Institute of Standards and Technology (NIST). Other suitable dye solution containing known molar absorptivity and concentration which is traceable to NIST or national authority may also be useful. 
     The validation method  700  starts by automatically dispensing a prescribed amount of test solution  714 A. The test solution  714 A is dispensed from the reagent bottle  614  through the reagent dispensing pipette  613  into an empty optical analysis cell  602  at the reagent discharge position. For example, when an empty optical analysis cell reaches the reagent discharge position DC2, the reagent pipette sucks and holds a prescribed amount of test solution  714 A at the suction position SC2 on the reagent table  611 . The prescribed amount of test solution  714 A, for example, should be sufficient to allow for photometric measurement later. The reagent dispensing unit  612  then rotates the filled reagent dispensing pipette in the direction indicated by arrow b from the suction position to the discharge position. For example, when the reagent dispensing pipette reaches the reagent discharge position, it discharges the test solution into the empty optical analysis cell at the discharge position on the turntable  603 . In this case, the test solution filled in the optical analysis cell forms a measurement target liquid  726 . 
     The validation method continues by rotating the optical analysis cell which is filled with the measurement target liquid to a measuring position, such as M74. The measurement target liquid in the optical analysis cell traverses the light L61 from the light source  625 A so that the colored condition of the blue dye solution is observed. Thus, optical characteristic of the measurement target liquid can be measured several times. 
     The light passes through the optical analysis cell which is filled with the measurement target liquid  726  and the transmitted light traverses a filter  725 B. The filter  725 B, for example, is a 730 nm filter and a signal having a magnitude representative of a transmitted light intensity is supplied to the converter  625 C. The analog signal is then converted to a digital signal which includes the transmittance data by the converter and the digital signal is fed to the microcomputer. The absorbance value of the blue dye component at wavelength of 730 nm is calculated from the intensity of the transmitted light and this absorbance value is stored in a memory. 
     In one embodiment, the unknown light path length of the optical analysis cell is determined using equation (2) as shown above. To determine the unknown light path length (L O ) of the optical analysis cell, equation (2) is rearranged as follows: 
                     L   O     =       A   730       a   b               (   3   )               
where
         L O =light path length of the optical analysis cell,   A 730 =is the measured absorbance value of the blue dye solution in the optical analysis cell at wavelength of 730 nm,   ε 730 =molar absorptivity of the blue dye, which is a physical constant of the blue dye at wavelength 730 nm, and   C=concentration of the blue dye.       

     For simplicity, the product of ε 730 C may be referred to as a b . Since the concentration (C) and molar absorptivity of the blue dye component at wavelength of 730 nm (ε 730 ) of the test solution  714 A are constant and known while the absorbance value of the blue dye at wavelength of 730 nm (A 730 ) is obtained from the photometric measurement of the intensity of the transmitted light which passes through the measurement target liquid  726  in the optical analysis cell  602 , the light path length (L O ) of the optical analysis cell can be determined based on equation (3) above. The calculated light path length data of the optical analysis cell is thus obtained and recorded accordingly in the memory of the microcomputer. The validation process continues by determining the light path length of adjacent and subsequent optical analysis cells and the calculated light path length data of these optical analysis cells are recorded and stored accordingly in the memory. 
     To validate or verify the accuracy of the light path length of the optical analysis cell, the light path length (L O ) as determined above is compared against the light path length value (L F ) provided by the manufacturer of the optical analysis cell or compared against the light path length value used to perform normal operation of the automated analyzer. If the calculated light path length (L O ) based on the validation method above is different than the light path length value (L F ) used to perform normal operation of the automated analyzer, this implies that the light path length of the optical analysis cell is not fixed or constant. As such, to improve the reliability of the results obtained from the automated analyzer, the user may input or choose the calculated light path length (L O ) based on the validation method above prior to initiating the normal operation of the automated analyzer. 
     As shown in  FIG. 7A , to verify or validate the accuracy of the light path length of the optical analysis cell, the reagent bottle is filled with a test solution  714 A. The test solution, for example, is a blue dye solution with known molar absorptivity and concentration of the blue dye component having absorbance maxima at 730 nm. The reagent dispensing pipette then dispenses the test solution  714 A in a sufficient amount into the optical analysis cell  602  to form the measurement target liquid  726  to enable photometric measurement. The sample dispensing pipette  618  and the diluent pipette  621  are not used to dispense the test solution  714 A as shown in  FIG. 7A . 
     In an alternative embodiment, in the event that the dispensing capability of reagent dispensing pipette  613  is limited, the validation method  700  can be modified such that the sample bottles  619  and/or the diluent bottle  623  are filled with the test solution  714 A, such as a blue dye solution containing known molar absorptivity and concentration of the blue dye component having absorbance maxima at 730 nm as shown in  FIG. 7B . In such case, the sample dispensing pipette  618 , the reagent dispensing pipette  613  and the diluent pipette  621  are together deployed to dispense sufficient amount of test solution  714 A, such as the blue dye solution, to allow for photometric measurements to be performed. 
     For example, the validation method may initiate with dispensing small prescribed amount of test solution  714 A from the sample dispensing pipette  618  into an empty optical analysis cell  602  at the discharge position DC1 as shown in  FIG. 7B . The filled optical analysis cell then rotates to the reagent dispensing position DC2. A small prescribed amount of test solution  714 A is dispensed from the reagent dispensing pipette  613  into the filled optical analysis cell at DC2. The method continues to rotate the filled optical analysis cell to a diluent discharge position DC3 of which a diluent dispensing pipette  621  is used to discharge a prescribed amount of test solution  714 A. In this case, the total test solutions which are dispensed by the sample dispensing pipette, the reagent dispensing pipette and the diluent dispensing pipette in the optical analysis cell form the measurement target liquid  726  which is in sufficient amount to allow for photometric measurements. The validation method continues by rotating the optical analysis cell which is filled with the measurement target liquid to a measuring position, such as M74. The measurement target liquid in the optical analysis cell traverses the light L61 from the light source  625 A so that the colored condition of the blue dye solution is observed. Thus, optical characteristic of the measurement target liquid can be measured several times and the light path length of the optical analysis cell (L O ) is calculated based on equation (3) as described above. To validate or verify the accuracy of the light path length of the optical analysis cell, the light path length (L O ) as calculated above is compared against the light path length value (L F ) provided by the manufacturer of the optical analysis cell or compared against the light path length value used to perform normal operation of the automated analyzer. 
     The validation process  700  as shown in  FIG. 7B  continues by determining the light path length of adjacent and subsequent optical analysis cells and the calculated light path length data of these optical analysis cells are recorded and stored accordingly in the memory. 
     The validation method  700  as described in  FIGS. 7A and 7B  offers several advantages. For example, the validation method  700  as described in  FIGS. 7A and 7B  is able to verify or validate the accuracy of the light path length of an optical analysis cell used in an automated analyzer. The results obtained by the validation method  700  are standardized and traceable to NIST or national authority. For instance, the parameters of the test solution having the blue dye component are traceable to NIST or national authority. In addition, the validation method  700  is relatively fast and easy to be performed. 
     As described earlier, it is also possible that the actual dispensed volume of a dispensing pipette used in an automated analyzer is above or below the amount as prescribed or defined by the user. As such, the concentration of component of analysis as obtained from the automated analyzer which is calculated based on equation (2) above may not be reliable. A validation method to determine or verify the accuracy of the dispensed volume of a dispensing pipette used in an automated analyzer will now be described.  FIG. 8  shows a validation method  800  to determine or verify the accuracy of the dispensed volume of a dispensing pipette used in the automated analyzer. As shown in  FIG. 8 , the automated analyzer includes the same elements as that described in  FIG. 6 . For example, the automated analyzer includes a sample section  650 , a reagent section  655 , a diluent section  660 , a reaction section  665  and an analysis section (not shown). As such, common features and features having the same reference numerals in  FIG. 6  will not be described in detail. In one embodiment, to conduct the validation method  800 , a measurement section  875  and a validation section  880  are provided. The measurement section and the validation section, in one embodiment, are provided separately from the automated analyzer. It is understood that the measurement section and validation section may be provided as part of the automated analyzer. 
     Referring to  FIG. 8 , the measurement section  875  includes first and second subsections  875   a  and  875   b . The first measurement subsection  875   a  includes a weighing unit  840 . As shown, the first measurement subsection  875   a  is provided adjacent to the diluent section  660 . It is understood that the first measurement subsection may be disposed at other suitable location. The weighing unit  840  includes a weighing machine  840 A for measuring, for example, the weight of the diluent dispensing pipette  621  with or without diluent. It is understood that the weighing machine  840 A may also be used to measure the weight of other filled or unfilled dispensing pipette. 
     The validation section  880  includes a measurement microplate or an optical measurement plate system  832 . The measurement microplate includes a plurality of retention grooves or wells  833 . The validation section also includes a transfer pipette  830  for dispensing solution for validation purposes as will be described later. As shown in  FIG. 8 , the second measurement subsection  875   b  is provided adjacent to the validation section  880 . It is understood that the second measurement subsection may also be disposed at other suitable location. The second measurement subsection  875   b , for example, includes a weighing unit  846  having a weighing machine  846 A for measuring, for example, the weight of the transfer pipette  830  with or without solution therein. The weighing unit  846  is disposed on a measuring table  845 . 
     The validation method  800  to verify whether the actual dispensed volume of a dispensing pipette under test (V AC ) is the same as the volume predefined by the user (V U ) will now be described. In one embodiment, the actual dispensed volume of a dispensing pipette under test is determined based on a dual dye ratio method. In one embodiment, the sample dispensing pipette  618  is chosen as the dispensing pipette under test as shown in  FIG. 8 . To determine the accuracy of the dispensed volume of the sample dispensing pipette  618 , the sample cup  619  is provided with a test solution  819 A. The test solution  819 A may be referred to as a first dye solution. The test solution  819 A contained in the sample cup, in one embodiment, is a dye solution containing two dye components. For example, the two dye components of the test solution  819 A includes a first dye component, which is a red dye component having distinct absorbance at 520 nm and a second dye component, which is a blue dye component having distinct absorbance maxima at 730 nm. In one embodiment, the molar absorptivity (ε) and concentration (C) of the two dye components are known and include known errors (uncertainty) traceable to NIST. Other suitable dye solution having two dye components with known molar absorptivity and concentration traceable to NIST may also be useful. 
     The validation method  800  starts by automatically dispensing an amount of test solution  819 A from the sample cup  619  through the sample dispensing pipette  618  into an empty optical analysis cell  602  at the sample discharge position. For example, when an empty optical analysis cell  602  reaches the sample discharge position DC1, the sample dispensing pipette  618  sucks and holds an amount of the test solution  819 A at the suction position SC1 on the sample table  616 . The amount of test solution  819 A dispensed by the sample dispensing pipette at this stage is supposed to be the same as the dispensed volume of sample solution predefined by the user (V U ) when the automated analyzer performs its normal operation. The sample dispensing unit  617  then rotates the filled sample dispensing pipette  618  in the direction indicated by arrow c from the suction position to the discharge position DC1. For example, when the sample dispensing pipette  618  reaches the sample discharge position DC1, it discharges the test solution  819 A into the empty optical analysis cell  602  at the discharge position DC1 on the turntable  603 . 
     The amount of the test solution  819 A dispensed by the sample dispensing pipette  618  into the optical analysis cell  602  may not be sufficient to allow for photometric measurements. As such, the validation process  800  continues to rotate the filled optical analysis cell to a diluent discharge position. For example, when the filled optical analysis cell reaches the diluent discharge position, such as the diluent filling position DC3, a prescribed amount of a diluent  823 A is dispensed into the optical analysis cell which is filled with test solution  819 A. For example, the user manually aspirates a prescribed amount of diluent  823 A from a diluent bottle  623  using a diluent dispensing pipette  621  such that the total volume in the filled optical cell is at about 200 μl. Other suitable amount of diluent may also be useful so long as the total volume of the filled optical cell is sufficient for photometric measurement for validation later. In one embodiment, the diluent  823 A includes a dye solution. The diluent  823 A may be referred to as a second dye solution. The dye solution of the diluent  823 A includes a third dye component, which is a blue dye component having distinct absorbance maxima at 730 nm with known molar absorptivity and concentration and includes known errors (uncertainty) traceable to NIST. The concentration of the blue dye component in the diluent  823 A is at the same concentration as the blue dye component in the test solution  819 A. 
     In one embodiment, the filled diluent dispensing pipette is placed on the weighing machine  840 A at the first measurement subsection  875   a  and the weight of the filled diluent pipette is measured using gravimetric method. The weight value of the filled diluent pipette (W81) is recorded. 
     The user then transfers the diluent  823 A to the filled optical analysis cell at the diluent discharge position DC3. Once the diluent is discharged into the filled optical analysis cell, the emptied diluent pipette  621  is put on the weighing machine  840 A at the first measurement subsection  875   a . The weight of the emptied diluent dispensing pipette (W82) is measured using gravimetric method and is recorded accordingly. As such, the amount of diluent injected into the optical analysis cell is determined on the basis of the weight difference of the diluent dispensing pipette  621  before and after dispensing. Further, this is also to ensure that the prescribed amount of diluent is completely dispensed into the optical analysis cell and no diluent remains in the diluent dispensing pipette  621 . 
     The test solution  819 A and diluent  823 A in the optical analysis cell  602  are mixed by a mixing mechanism (not shown), such as an agitator, to form a measurement target liquid  826 . The purpose of the diluent is to fill the optical analysis cell such that it has a total volume which is sufficient to allow for optical or photometric measurements. 
     The validation method  800  continues by rotating the optical analysis cell which is filled with the test solution and diluent to a prescribed position awaiting to be transferred to the validation section  880 . In one embodiment, the validation method  800  continues by transferring the entire measurement target liquid  826  to the measurement microplate  832  for verification at the validation section  880  as shown by arrow d. 
     For example, the measurement target liquid  826  in the optical analysis cells  602  is removed by the user using a transfer pipette  830 . The filled transfer pipette is placed on the weighing machine  846 A at the second measurement subsection  875   b  and the weight of the filled transfer pipette is measured using gravimetric method. The weight value of the filled transfer pipette (W83) is recorded. 
     Using the transfer pipette  830 , the user then transfers the measurement target liquid  826  to one of the plurality of retention wells  833  in the measurement microplate  832  on a validation rack  831  at the validation section  880 . Once the measurement target liquid  826  is discharged into the retention well, the emptied transfer pipette is put on the weighing machine  846 A at the second measurement subsection  875   b . The weight of the emptied transfer pipette (W84) is measured using gravimetric method and is recorded accordingly. Thus, the amount of measurement target liquid injected into the retention well is determined on the basis of the weight difference of the transfer pipette before and after dispensing. Further, this is also to ensure that the entire measurement target liquid  826  is completely dispensed into the retention well and no measurement target liquid remains in the transfer pipette. 
     The validation process  800  continues by measuring absorbance of the red and blue dye components in the measurement target transfer liquid  826 A placed in the retention well  833  using a second optical absorbance detection unit  841  as shown in  FIGS. 8 and 9 . 
     Referring to  FIG. 9 , the optical absorbance detection unit  841  has a white light source  841 A that emits a white light L82. The light L82 passes through the retention well  833  which is filled with the measurement target liquid  826 A having red and blue dye components in a vertical direction. The transmitted light traverses a first filter  841 B which allows the wavelength of 730 nm necessary for the blue dye component and a first analog signal having a magnitude representative of a transmitted light intensity of the blue dye component is supplied to a converter  841 D. The analog signal is then converted to a first digital signal which includes the transmittance data of the blue dye component by the converter and the digital signal is fed to a processing unit  844  having a microcomputer. The absorbance value of the blue dye component (A 730 ) in the measurement target liquid  826 A in the retention well is calculated from the measured transmittance data and this absorbance value is stored in a memory. Then, the first filter  841 B is replaced with a second filter  841 C which allows the wavelength of 520 nm necessary for the red dye component. The light passes through the retention well  833  which is filled with the red and blue dye components and the transmitted light traverses a second filter  841 C and a second analog signal having a magnitude representative of a transmitted light intensity of the red dye component is supplied to the converter  841 D. The analog signal is then converted to a second digital signal which includes the transmittance data of the red dye component by the converter and the digital signal is fed to the processing unit  844 . The absorbance value of the red dye component (A 520 ) in the measurement target liquid  826 A in the retention well is calculated from the measured transmittance data and this absorbance value is stored in a memory. 
     Thus, the absorbance values of the red and blue dye components are measured for the measurement target liquid  826 A in the retention well  833  at both wavelengths. These absorbance values collected from the retention well in the microplate are used to calculate the actual dispensed volume (V AC ) of the dispensing pipette under test, which is the sample dispensing pipette  618  in this embodiment. 
       FIGS. 10A-10C  shows the determination of the actual dispensed volume (V AC ) of the sample dispensing pipette  618 . For illustration purpose, the geometric shape of the retention wells  833  in the microplate  832  is shown as a truncated cone shape. To ensure that the calculation of the actual dispensed volume of the sample dispensing pipette is accurate, every retention well in the microplate is measured with a coordinate measuring machine and a photometer to determine the mean bottom diameter (D) and mean taper angle (θ) of the sidewall of each of the wells as shown in  FIG. 10A . The geometric dimensions of each of the retention wells are encoded in a bar code affixed to the microplate. These geometric dimensions will be used to calculate the actual dispensed volume of the sample dispensing pipette. 
     The calculation of the liquid depth (L G ) in the retention well  833  will now be described. As described earlier, the concentration of the blue dye component in the diluent  823  is the same as the concentration of the blue dye component in the test solution  819 A. Therefore, equation (3) as described above can be used to calculate the liquid depth in the retention well, which is equivalent to path length of light which passed through the measurement target liquid  826 A in the retention well  833  as shown in  FIG. 10B . The liquid depth (L G ) can be determined by the following equation (4): 
                     L   G     =       A   730       a   b               (   4   )               
where
         L G =liquid depth in the retention well which is equivalent of light path length which passes through the measurement target liquid  826 A in the retention well,   A 730 =absorbance value of the blue dye component in the measurement target liquid  826 A at wavelength of 730 nm measured by the second optical absorbance detection unit  841 ,   a b =absorption per unit path length of the blue dye component at 730 nm, which is the product of (ε 730 C), where ε 730  is the molar absorptivity of the blue dye component, which is a physical constant of the blue dye at wavelength 730 nm, and C is the concentration of the blue dye component of the test solution or diluent.       

     Since the concentration (C) and molar absorptivity of the blue dye component at wavelength of 730 nm of the test solution  819 A or diluent  823 A are known while the absorbance value of the blue dye component at wavelength of 730 nm (A 730 ) is obtained from the photometric measurement of the intensity of the transmitted light passes through the measurement target liquid  826 A in the retention well, the light path length (L G ) can be determined. 
     Once the liquid depth (L G ) is determined, the geometrical equation for the volume of the truncated cone can be used to determine the total volume of measurement target liquid (V TG ) in the retention well  833 . The calculation of the total volume of measurement target liquid in the retention well (V TG ) is based on the liquid depth (L G ) as determined from equation (4) and the geometric dimensions of the retention well  833  of the microplate, as shown in equation (5) below: 
     
       
         
           
             
               
                 
                   
                     V 
                     TG 
                   
                   = 
                   
                     
                       π 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         L 
                         G 
                       
                       ⁢ 
                       
                         
                           D 
                           2 
                         
                         4 
                       
                     
                     + 
                     
                       π 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         DL 
                         G 
                         2 
                       
                       ⁢ 
                       
                         
                           tan 
                           ⁡ 
                           
                             ( 
                             θ 
                             ) 
                           
                         
                         2 
                       
                     
                     + 
                     
                       π 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         L 
                         G 
                         3 
                       
                       ⁢ 
                       
                         
                           
                             tan 
                             2 
                           
                           ⁡ 
                           
                             ( 
                             θ 
                             ) 
                           
                         
                         3 
                       
                     
                   
                 
               
               
                 
                   ( 
                   5 
                   ) 
                 
               
             
           
         
       
     
     With the calculated total volume of measurement target liquid in the retention well (V TG ) above, the actual dispensed volume (V AC ) of the dispensing pipette under test, which is the sample dispensing pipette in this case, can be determined based on equation (6), which is similar to equation (1), as shown below: 
                     V   AC     =         V   TG     ⁡     (       a   b       a   r       )       ⁢     (       A   520       A   730       )               (   6   )               
where
         V AC =the actual dispensed volume of the dispensing pipette under test,   V TG =total volume of measurement target liquid  826 A in the retention well as calculated based on equation (5) above,   a b =absorption per unit path length of the blue dye component at 730 nm, which is the product of (ε 730 C),   a r =absorption per unit path length of the red dye component at 520 nm, which is the product of (ε 520 C), where ε 520  is the molar absorptivity of the red dye component, which is a physical constant of the red dye at wavelength 520 nm, and C is the concentration of the red dye component of the test solution,   A 730 =absorbance value of the blue dye component at wavelength of 730 nm measured by the second optical absorbance detection unit  841 , and   A 520 =absorbance value of the red dye component at wavelength of 520 nm measured by the second optical absorbance detection unit  841 .       

     The concentration (C) and molar absorptivity (ε 730 ) of the blue dye component at wavelength of 730 nm of the test solution  819 A or diluent  823 A as well as the concentration (C) and the molar absorptivity (ε 520 ) of the red dye component at the wavelength of 520 nm of the test solution  819 A are known. On the other hand, the absorbance value of the blue dye component at wavelength of 730 nm (A 730 ) and the absorbance value of the red dye component at wavelength of 520 nm are obtained from the photometric measurement of the intensity of the transmitted light passes through the measurement target liquid  826 A in the retention well  833 . Since all these values are known and the V TG  is obtained from the calculation based on equation (5), the actual dispensed volume (V AC ) of a dispensing pipette under test can be determined and is transmitted to a validation result processing unit  847 . 
     To validate or verify the accuracy of the dispensed volume of the sample dispensing pipette  618 , the actual dispensed volume (V AC ) as determined above is compared against the volume predefined by the user (V U ). If the calculated actual dispensed volume (V AC ) based on the validation method  800  above is different than the dispensing volume of the sample dispensing pipette predefined by the user (V U ) for normal operation of the automated analyzer, this implies that the sample dispensing pipette  618  does not accurately or precisely dispense the amount of sample solution as predefined by the user during normal operation of the automated analyzer. As such, to improve the reliability of the results obtained from the automated analyzer, the user may need to fine tune, calibrate or adjust the sample dispense pipette accordingly prior to initiating the normal operation of the automated analyzer. 
     The actual dispensed volume (V AC ) as determined above can also be used to check whether the volume dispensed by the sample dispensing pipette is within a dispensing accuracy curve DT as described in  FIG. 4 . For example, when the result of the actual dispensed volume (V AC ) is within the area demarcated by the dispensing accuracy curve DT, the dispensing accuracy of the sample dispensing pipette of the automated analyzer is within the allowed range and the user need not fine tune or adjusts the sample dispensing pipette. On the other hand, if the actual dispensed volume (V AC ) as determined above is out of the area demarcated by the dispensing accuracy curve DT as shown in  FIG. 4 , the user is required to take necessary action to make further adjustment to the sample dispensing pipette. 
     The validation method  800  as described in  FIG. 8  offers several advantages. For example, the validation method  800  as described in  FIG. 8  is able to verify or validate the accuracy of the dispensed volume of any dispensing pipette in an automated analyzer. The validation method  800  is able to measure small volumes which are generally dispensed by any dispensing pipette in an automated analyzer. In addition, the results obtained by the validation method  800  are standardized and traceable to NIST or national authority. For instance, the parameters of the dye solutions and the geometric dimensions of the retention wells of the measurement microplate are properly characterized and traceable to NIST or national authority. Further, the results obtained from the validation method  800  is also highly reliable as the validation method  800  also includes measurements of the diluent dispensing pipette and the transfer pipette before and after dispensing using gravimetric method which ensure or confirm that no solution remains in these pipettes after dispensing. Moreover, the validation method  800  also allows for high swiftness and molecular level volumetric measurement to be achieved. 
     As described, the validation method  800  as described in  FIG. 8  is able to verify or validate the accuracy of the dispensed volume of any dispensing pipette in an automated analyzer. The validation method  800  may be modified to verify or validate the accuracy of the dispensed volume of another dispensing pipette, such as the reagent dispensing pipette. A validation method to determine or verify the accuracy of the dispensed volume of the reagent dispensing pipette  613  in an automated analyzer will now be described.  FIG. 11  shows a validation method  1100  to determine or verify the accuracy of the dispensed volume of a dispensing pipette under test, which is the reagent dispensing pipette, in the automated analyzer  600  as described in  FIG. 6 . As shown in  FIG. 11 , the automated analyzer includes the same elements as that described in  FIG. 8 . For example, the automated analyzer includes a sample section  650 , a reagent section  655 , a diluent section  660 , a reaction section  665  and an analysis section (not shown). To perform the validation method  1100 , a measurement section  875  and a validation section  880  which are the same as that described in  FIG. 8  are provided. As such, common features and features having the same reference numerals in  FIG. 8  will not be described in detail. 
     The validation method  1100  to verify whether the actual dispensed volume of the dispensing pipette under test (V AC ) is the same as the volume predefined by the user (V U ) will now be described. In one embodiment, the actual dispensed volume of a dispensing pipette under test is determined based on a dual dye ratio method. In one embodiment, the dispensing pipette under test is the reagent dispensing pipette  613 . To determine the accuracy of the dispensed volume of the reagent dispensing pipette  613 , the reagent bottle is provided with the test solution  819 A. The test solution  819 A may be referred to as a first dye solution. The test solution  819 A is the same as the test solution  819 A described in  FIG. 8 . The test solution  819 A contained in the reagent bottle  614 , in one embodiment, is a dye solution containing two dye components. For example, the first dye component of the test solution  819 A includes a red dye component having distinct absorbance at 520 nm while the second dye component of the test solution  819 A includes a blue dye component having distinct absorbance maxima at 730 nm. In one embodiment, the molar absorptivity (ε) and concentration (C) of the two dye components are known and include known errors (uncertainty) traceable to NIST. Other suitable dye solution having two dye components with known molar absorptivity and concentration traceable to NIST may also be useful. 
     The validation method  1100  starts by automatically dispensing an amount of test solution  819 A from the reagent bottle  614  through the reagent dispensing pipette  613  into an empty optical analysis cell  602  at the reagent discharge position. For example, when an empty optical analysis cell  602  reaches the reagent discharge position DC2, the reagent dispensing pipette  613  sucks and holds an amount of the test solution  819 A at the suction position SC2 on the reagent table  611 . The amount of test solution  819 A dispensed by the reagent dispensing pipette at this stage is supposed to be the same as the dispensed volume of reagent solution predefined by the user (V U ) when the automated analyzer performs its normal operation. The reagent dispensing unit  612  then rotates the filled reagent dispensing pipette  613  in the direction indicated by arrow b from the suction position to the discharge position DC2. For example, when the reagent dispensing pipette  613  reaches the reagent discharge position DC2, it discharges the test solution  819 A into the empty optical analysis cell  602  at the discharge position DC2 on the turntable  603 . 
     The amount of the test solution  819 A dispensed by the reagent dispensing pipette  613  into the optical analysis cell  602  may not be sufficient to allow for photometric measurements. As such, the validation process  1100  continues to rotate the filled optical analysis cell to a diluent discharge position. For example, when the filled optical analysis cell reaches the diluent discharge position, such as the diluent filling position DC3, a prescribed amount of a diluent  823 A is dispensed into the optical analysis cell which is filled with test solution  819 A. For example, the user manually aspirates a prescribed amount of diluent  823 A from a diluent bottle  623  using a diluent dispensing pipette  621  such that the total volume in the filled optical cell is at about 200 μl. Other suitable amount of diluent may also be useful so long as the total volume of the filled optical cell is sufficient for photometric measurement for validation later. In one embodiment, the diluent  823 A includes a dye solution. The diluent  823 A may be referred to as a second dye solution. The diluent  823 A is the same as the diluent  823 A described in  FIG. 8 . The dye solution of the diluent  823 A includes a blue dye component having distinct absorbance maxima at 730 nm with known molar absorptivity and concentration. The concentration of the blue dye component in the diluent  823 A is at the same concentration as the blue dye component in the test solution  819 A. 
     In one embodiment, the filled diluent pipette  621  is placed on the weighing machine  840 A at the first measurement subsection  875   a  and the weight of the filled diluent pipette is measured using gravimetric method. The weight value of the filled diluent pipette (W111) is recorded. 
     The user then transfers the diluent  823 A to the filled optical analysis cell at the diluent discharge position DC3. Once the diluent is discharged into the filled optical analysis cell, the emptied diluent pipette  621  is put on the weighing machine  840 A at the first measurement subsection  875   a . The weight of the emptied diluent pipette (W112) is measured using gravimetric method and is recorded accordingly. As such, the amount of diluent injected into the optical analysis cell is determined on the basis of the weight difference of the diluent dispensing pipette before and after dispensing. Further, this is also to ensure that the prescribed amount of diluent is completely dispensed into the optical analysis cell and no diluent remains in the diluent pipette  621 . 
     The test solution  819 A and diluent  823 A in the optical analysis cell  602  are mixed by a mixing mechanism (not shown), such as an agitator, to form a measurement target liquid  826 . The purpose of the diluent is to fill the optical analysis cell such that it has a total volume which is sufficient to allow for optical or photometric measurements. 
     The validation method  800  continues by rotating the optical analysis cell which is filled with the test solution and diluent to a prescribed position awaiting to be transferred to the validation section  880 . In one embodiment, the validation method  1100  continues by transferring the entire measurement target liquid  826  to the measurement microplate  832  for verification at the validation section  880  as shown by arrow d. 
     For example, the measurement target liquid  826  in the optical analysis cells  602  is removed by the user using a transfer pipette  830 . The filled transfer pipette is placed on the weighing machine  846 A at the second measurement subsection  875   b  and the weight of the filled transfer pipette is measured using gravimetric method. The weight value of the filled transfer pipette (W113) is recorded. 
     Using the transfer pipette  830 , the user then transfers the measurement target liquid  826  to one of the plurality of retention wells  833  in the measurement microplate  832  on a validation rack  831  at the validation section  880 . Once the measurement target liquid  826  is discharged into the retention well, the emptied transfer pipette is put on the weighing machine  846 A at the second measurement subsection  875   b . The weight of the emptied transfer pipette (W114) is measured using gravimetric method and is recorded accordingly. Thus, the amount of measurement target liquid injected into the retention well is determined on the basis of the weight difference of the transfer pipette before and after dispensing. Further, this is also to ensure that the entire measurement target liquid  826  is completely dispensed into the retention well and no measurement target liquid remains in the transfer pipette. 
     The validation process  1100  continues by measuring absorbance of the red and blue dye components in the measurement target transfer liquid  826 A placed in the retention wells  833  using a second optical absorbance detection unit  841  as shown in  FIG. 9 . The absorbance values of the red and blue dye components are measured for the measurement target liquid  826 A in the retention well  833  at both wavelengths, the same as that already described in  FIG. 9 . These absorbance values collected from the retention well in the microplate are used to calculate the actual dispensed volume (V AC ) of the dispensing pipette under test, which is the reagent dispensing pipette  613  in this embodiment. 
     The determination of the actual dispensed volume (V AC ) of the reagent dispensing pipette  613  is the same as that illustrated and described in  FIGS. 10A-10C  and therefore will not be described again. For example, equations (4)-(5) are used to determine the liquid depth (L G ) and the total volume of measurement target liquid in the retention well V TG . With these results from these equations, the actual dispensed volume (V AC ) of the reagent dispensing pipette can be determined based on equation (6) above. 
     The concentration (C) and molar absorptivity (ε 730 ) of the blue dye component at wavelength of 730 nm of the test solution  819 A or diluent  823 A as well as the concentration (C) and the molar absorptivity (ε 520 ) of the red dye component at the wavelength of 520 nm of the test solution  819 A are known. On the other hand, the absorbance value of the blue dye component at wavelength of 730 nm (A 730 ) and the absorbance value of the red dye component at wavelength of 520 nm (A 520 ) are obtained from the photometric measurement of the intensity of the transmitted light passes through the measurement target liquid  826 A in the retention well. Since all these values are known and the V TG  is obtained from the calculation based on equation (5), the actual dispensed volume (V AC ) of the reagent dispensing pipette  613  can be determined. 
     To validate or verify the accuracy of the dispensed volume of the reagent dispensing pipette  613 , the actual dispensed volume (V AC ) as determined above is compared against the volume predefined by the user (V U ). If the calculated actual dispensed volume (V AC ) based on the validation method  1100  above is different than the dispensing volume of the reagent dispensing pipette predefined by the user (V U ) for normal operation of the automated analyzer, this implies that the reagent dispensing pipette  613  does not accurately or precisely dispense the amount of reagent solution as predefined by the user during normal operation of the automated analyzer. As such, to improve the reliability of the results obtained from the automated analyzer, the user may need to fine tune, calibrate or adjust the reagent dispense pipette  613  accordingly prior to initiating the normal operation of the automated analyzer. 
     The actual dispensed volume (V AC ) of the reagent dispensing pipette as determined above can also be used to check whether the volume dispensed by the reagent dispensing pipette is within a dispensing accuracy curve DT as described in  FIG. 4 . For example, when the result of the actual dispensed volume (V AC ) is within the area demarcated by the dispensing accuracy curve DT, the dispensing accuracy of the reagent dispensing pipette of the automated analyzer is within the allowed range and the user need not fine tune or adjusts the reagent dispensing pipette. On the other hand, if the actual dispensed volume (V AC ) as determined above is out of the area demarcated by the dispensing accuracy curve DT as shown in  FIG. 4 , the user is required to take necessary action to make further adjustment to the reagent dispensing pipette. 
     The validation method  1100  as described in  FIG. 11  offers similar or the same advantages as that described in  FIG. 8 . As such, these advantages will not be described. 
     The validation methods  800  and  1100  as described in  FIG. 8  and  FIG. 11  can be used to verify the accuracy of the dispensed volume of any dispensing pipette of the automated analyzer. It is a simple and flexible method. All the user needs to do is to use the dispensing pipette under test to suck and dispense the test solution  819 A and provide the diluent  823 A into the optical analysis cell to form a measurement target liquid which is sufficient to allow for photometric measurement. The test solution, for example, includes first and second dye components while the diluent, for example, includes a third dye component which is at the same concentration as the second dye component of the test solution. As such, any suitable dye solutions which are standardized and traceable to NIST may be used. In addition, although the retention well is presented as having a truncated cone shape, it is understood that the well may also be in other shapes, such as but not limited to square shape. In such case, the user needs to modify equation (5) such that the geometrical equation for the volume of the square shape retention well is used to determine the total volume of measurement target liquid (V TG ) in the retention well  833 . 
     The preferred embodiment of the invention is illustrative of the invention rather than limiting of the invention. It is to be understood that revisions and modifications may be made to methods and systems described herein while still providing a manufacturing automation system and an automated method for movement of material that fall within the scope of the included claims. All matters hitherto set forth herein or shown in the accompanying figures are to be interpreted in an illustrative and non limiting sense.