ASTM_D_6122_-_13.pdf

Designation:D612213Standard Practice forValidation of the Performance of Multivariate Online,At-Line,and Laboratory Infrared Spectrophotometer BasedAnalyzer Systems1This standard is issued under the fixed designation D6122;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONOperation of a laboratory or process stream analyzer system typically involves four sequentialactivities.(1)Analyzer CalibrationWhen an analyzer is initially installed,or after majormaintenance has been performed,diagnostic testing is performed to demonstrate that the analyzermeets the manufacturers specifications and historical performance standards.These diagnostic testsmay require that the analyzer be adjusted so as to provide predetermined output levels for certainreference materials.(2)CorrelationOnce the diagnostic testing is completed,process streamsamples are analyzed using both the analyzer system and the corresponding primary test method(PTM).A mathematical function is derived that relates the analyzer output to the primary test method(PTM).The application of this mathematical function to an analyzer output produces a predictedprimary test method result(PPTMR).(3)Probationary ValidationOnce the relationship betweenthe analyzer output and PTMRs has been established,a probationary validation is performed using anindependent but limited set of materials that were not part of the correlation activity.This probationaryvalidation is intended to demonstrate that the PPTMRs agree with the PTMRs to within user-specifiedrequirements for the analyzer system application.(4)General and Continual ValidationAfter anadequate number of PPTMRs and PTMRs have been accrued on materials that were not part of thecorrelation activity,a comprehensive statistical assessment is performed to demonstrate that thePPTMRs agree with the PTMRs to within user-specified requirements.Subsequent to a successfulgeneral validation,quality assurance control chart monitoring of the differences between PPTMR andPTMR is conducted during normal operation of the process analyzer system to demonstrate that theagreement between the PPTMRs and the PTMRs established during the General Validation ismaintained.This practice deals with the third and fourth of these activities.1.Scope*1.1 This practice covers requirements for the validation ofmeasurements made by laboratory or process(online or at-line)near-or mid-infrared analyzers,or both,used in the calculationof physical,chemical,or quality parameters(that is,properties)of liquid petroleum products.The properties are calculatedfrom spectroscopic data using multivariate modeling methods.The requirements include verification of adequate instrumentperformance,verification of the applicability of the calibrationmodel to the spectrum of the sample under test,and verificationof equivalence between the result calculated from the infraredmeasurements and the result produced by the primary testmethod used for the development of the calibration model.When there is adequate variation in property level,the statis-tical methodology of Practice D6708 is used to provide generalvalidation of this equivalence over the complete operatingrange of the analyzer.For cases where there is inadequateproperty variation,methodology for level specific validation isused.1.2 Performance Validation is conducted by calculating theprecision and bias of the differences between results from theanalyzer system(or subsystem)produced by application of themultivariate model,(such results are herein referred to asPredicted Primary Test Method Results(PPTMRs),versus thePrimary Test Method Results(PTMRs)for the same sampleset.Results used in the calculation are for samples that are notused in the development of the multivariate model.The1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.25 on Performance Assessment and Validation of Process StreamAnalyzer Systems.Current edition approved May 1,2013.Published June 2013.Originallyapproved in 1997.Last previous edition approved in 2010 as D6122 10.DOI:10.1520/D6122-13.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 calculated precision and bias are statistically compared touser-specified requirements for the analyzer system applica-tion.1.2.1 For analyzers used in product release or productquality certification applications,the precision and bias re-quirement for the degree of agreement are typically based onthe site or published precision of the Primary Test Method.NOTE1In most applications of this type,the PTM is the specification-