Designation:D6617−21AnAmericanNationalStandardStandardPracticeforLaboratoryBiasDetectionUsingSingleTestResultfromStandardMaterial1ThisstandardisissuedunderthefixeddesignationD6617;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONDuetotheinherentimprecisioninalltestmethods,alaboratorycannotexpecttoobtainthenumericallyexactacceptedreferencevalue(ARV)ofacheckstandard(CS)materialeverytimeoneistested.ResultsthatarereasonablyclosetotheARVshouldprovideassurancethatthelaboratoryisperformingthetestmethodeitherwithoutbias,orwithabiasthatisofnopracticalconcern,hencerequiringnointervention.ResultsdifferingfromtheARVbymorethanacertainamount,however,shouldleadthelaboratorytotakecorrectiveaction.1.Scope*1.1ThispracticecoversamethodologyforestablishinganacceptabletolerancezoneforthedifferencebetweenasingleresultobtainedforaCheckStandard(CS)fromasingleimplementationofatestmethodusingasinglemeasurementsystematalaboratoryversusitsAcceptedReferenceValue(ARV),basedonuser-specifiedTypeIerror,theuser-establishedmeasurementsystemprecisionfortheexecutionofthetestmethod,thestandarderroroftheARV,andapresumedhypothesisthatthemeasurementsystemasoperatedbythelaboratoryintheexecutionofthetestmethodisnotbiased.NOTE1—Throughoutthispractice,theterm“user”referstotheuserofthispractice,andtheterm“laboratory”(see1.1)referstotheorganizationorentitythatisperformingthetestmethod.1.2Forthetolerancezoneestablishedin1.1,amethodologyispresentedtoestimatetheprobabilitythatthesingletestresultwillfalloutsidethezone,intheeventthatthepresumedhypothesisisnottrueandthereisabias(positiveornegative)ofauser-specifiedmagnitudethatisdeemedtobeofpracticalconcern.1.3ThispracticeisintendedforASTMCommitteeD02testmethodsthatproduceresultsonacontinuousnumericalscale.1.4Thispracticeassumesthatthenormal(G...
