ASTM E691-2009e1 测定试验方法精密度实施的多个实验室间的研究的标准实施规程

作者:标准资料网 时间:2024-05-15 20:09:46  浏览:8720   来源:标准资料网

【英文标准名称】:StandardPracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod
【原文标准名称】:测定试验方法精密度实施的多个实验室间的研究的标准实施规程
【标准号】:ASTME691-2009e1
【标准状态】:现行
【国别】:
【发布日期】:2009
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E11.20
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:精密度;重复性;再现性;反复限定;国际实验室间试验;统计方法
【英文主题词】:precision;repeatability;reproducibility;repeatabilitylimit;Interlaboratorytesting;Statisticalmethods
【摘要】:ASTMregulationsrequireprecisionstatementsinalltestmethodsintermsofrepeatabilityandreproducibility.Thispracticemaybeusedinobtainingtheneededinformationassimplyaspossible.ThisinformationmaythenbeusedtoprepareaprecisionstatementinaccordancewithPracticeE177.TestMethodandProtocol8212;Inthispractice,thetermx201C;testmethodx201D;isusedbothfortheactualmeasurementprocessandforthewrittendescriptionoftheprocess,whilethetermx201C;protocolx201D;isusedforthedirectionsgiventothelaboratoriesforconductingtheILS.Observations,TestDeterminationsandTestResults:5.3.1Atestmethodoftenhasthreedistinctstages,thedirectobservationofdimensionsorproperties,thearithmeticcombinationoftheobservedvaluestoobtainatestdetermination,andthearithmeticcombinationofanumberoftestdeterminationstoobtainthetestresultofthetestmethod.Inthesimplestoftestmethodsasingledirectobservationisboththetestdeterminationandthetestresult.Forexample,thetestmethodmayrequirethemeasurementofthemassofatestspecimenpreparedinaprescribedway.Anothertestmethodmayrequirethemeasurementoftheareaofthetestspecimenaswellasthemass,andthendirectthatthemassbedividedbytheareatoobtainthemassperunitareaofthespecimen.Thewholeprocessofmeasuringthemassandtheareaandcalculatingthemassperunitareaisatestdetermination.Ifthetestmethodspecifiesthatonlyonetestdeterminationistobemade,thenthetestdeterminationvalueisthetestresultofthetestmethod.Sometestmethodsrequirethatseveraldeterminationsbemadeandthevaluesobtainedbeaveragedorotherwisecombinedtoobtainthetestresultofthetestmethod.Averagingofseveraldeterminationsisoftenusedtoreducetheeffectoflocalvariationsofthepropertywithinthematerial.Inthispractice,thetermx201C;testdeterminationx201D;isusedbothfortheprocessandforthevalueobtainedbytheprocess,exceptwhenx201C;testdeterminationvaluex201D;isneededforclarity.Thenumberoftestdeterminationsrequiredforatestresultshouldbespecifiedineachindividualtestmethod.Thenumberoftestresultsrequiredforaninterlaboratorystudyofatestmethodisspecifiedintheprotocolofthatstudy.TestSpecimensandTestUnits8212;Inthispracticeatestunitisthetotalquantityofmaterialneededforobtainingatestresultasspecifiedbythetestmethod.Theportionofthetestunitneededforobtainingasingletestdeterminationiscalledatestspecimen.Usuallyaseparatetestspecimenisrequiredforeachtestdetermination.Precision,Bias,andAccuracyofaTestMethod:5.5.1Whenatestmethodisappliedtoalargenumberofportionsofamaterial,thatareasnearlyalikeaspossible,thetestresultsobtainedneverthelesswillnotallhavethesamevalue.Ameasureofthedegreeofagreementamongthesetestresultsdescribestheprecisionofthetestmethodforthatmaterial.Numericalmeasuresofthevariabilitybetweensuchtestresultsprovideinversemeasuresoftheprecisionofthetestmethod.Greatervariabilityimpliessmaller(thatis,poorer)precisionandlargerimprecision.Thispracticeisdesignedonlytoestimatetheprecisionofatestmethod.Howe......