Designation:D7808−22StandardPracticeforDeterminingtheSitePrecisionofaProcessStreamAnalyzeronProcessStreamMaterial1ThisstandardisissuedunderthefixeddesignationD7808;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONWhenaprocessstreamanalyzerisusedtomonitororcontrolaprocess,theresultsproducedbytheanalyzeraretypicallyusedassurrogatesforvaluesthatwouldotherwisehavebeenobtainedviaanalysesofprocesssamplesusingaPrimaryTestMethod(PTM).SuccessfulapplicationoftheanalyzerrequiresthatthePredictedPrimaryTestMethodResult(PPTMR)producedbytheanalyzeragreeswiththePrimaryTestMethodResult(PTMR)towithinsomeuserspecifiedaccuracy(biasandprecision).Toachievethisgoal,itistypicallynecessarytodevelopacorrelationthatrelatesraw,UncorrectedAnalyzerResults(UARs)toPTMRs.ThecorrelationandtheanalyzersperformancearethenassessedduringtheanalyzervalidationtoestablishtheexpectedagreementbetweenthePPTMRandPTMR.Inestablishingthecorrelation,andassessingtheperformance,itisnecessarytoknowtheprecisionofboththePPTMRandthePTMR.TheprecisionofthePTMRsistypicallyestablishedthroughstatisticalqualitycontrolproceduresdescribedinD6299.TheprecisionofthePPTMRsisestablishedviaproceduresdescribedherein.Thetechniquesusedtodetermineprocessanalyzersiteprecisioncanalsobeusedforongoingqualitycontroloftheanalyzermeasurementsystem.1.Scope*1.1Thispracticedescribesaproceduretoquantifythesiteprecisionofaprocessanalyzerviarepetitivemeasurementofasingleprocesssampleoveranextendedtimeperiod.Theproceduremaybeappliedtomultipleprocesssamplestoobtainsiteprecisionestimatesatdifferentpropertylevels1.1.1ThesiteprecisionisrequiredforuseofthestatisticalmethodologyofD6708inestablishingthecorrelationbetweenanalyzerresultsandprimarytestmethodresultsusingPracticeD7235.1.1.2Thesiteprecisionisalsorequiredwhenemployingthestatistic...
