ASTM B762-1990(2010) 金属涂层和无机物涂层的不同抽样的标准试验方法

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【英文标准名称】:StandardTestMethodofVariablesSamplingofMetallicandInorganicCoatings
【原文标准名称】:金属涂层和无机物涂层的不同抽样的标准试验方法
【标准号】:ASTMB762-1990(2010)
【标准状态】:现行
【国别】:美国
【发布日期】:1990
【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】:B08.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:Coatingthickness;Destructivetesting--coatings;Inorganiccoatings;Metalliccoatings;Nondestructiveevaluation(NDE)--metallic/inorganiccoatings;Samplingelectrodepositedcoatings;Variablessampling
【摘要】:Samplinginspectionpermitstheestimationoftheoverallqualityofagroupofproductarticlesthroughtheinspectionofarelativelysmallnumberofproductarticlesdrawnfromthegroup.Thespecificationofasamplingplanprovidespurchasersandsellersameansofidentifyingtheminimumqualitylevelthatisconsideredtobesatisfactory.Becausesamplingplansyieldestimatesofthequalityofaproduct,theresultsoftheinspectionaresubjecttoerror.Throughtheselectionofasamplingplan,thepotentialerrorisknownandcontrolled.Samplinginspectionisusedwhenadecisionmustbemadeaboutwhattodowithaquantityofarticles.Thisquantitymaybeashipmentfromasupplier,articlesthatarereadyforasubsequentmanufacturingoperation,orarticlesreadyforshipmenttoacustomer.Insamplinginspection,arelativelysmallnumberofarticles(thesample)isselectedrandomlyfromalargernumberofarticles(theinspectionlot);thesampleisinspectedforconformancetotherequirementsplacedonthearticles.Basedontheresults,adecisionismadewhetherornotthelotconformstotherequirements.Sinceonlyaportionofaproductionlotisinspected,thequalityoftheuninspectedarticlesisnotknown.Thepossibilityexiststhatsomeoftheuninspectedarticlesarenonconforming.Therefore,basictoanysamplinginspectionplanisthewillingnessofthebuyertoacceptlotsthatcontainsomenonconformingarticles.Thenumberofnonconformingarticlesinacceptedlotsiscontrolledbythesizeofthesampleandthecriteriaofacceptancethatareplacedonthesample.Acceptancesamplingplansareusedforthefollowingreasons:Whenthecostofinspectionishighandtheconsequencesofacceptinganonconformingarticlearenotserious.When100%inspectionisfatiguingandboringand,therefore,likelytoresultinerrors.Wheninspectionrequiresadestructivetest,samplinginspectionmustbeused.Inacceptancesamplingbyvariables,thecoatingcharacteristicofeacharticleinthesampleismeasured.Usingthearithmeticmeanofthesevalues,thestandarddeviationoftheprocess,andthefactorkthatisfoundintheTables,anumberiscalculated(see9.3).Ifthisnumberequalsorexceedsthespecifiedminimum,theinspectionlotconformstotherequirements.Ifitisless,thelotdoesnotconform.Ifthestandarddeviationoftheprocessisnotknown,thestandarddeviationofthesampleiscalculatedandused.Theuseofasamplingplaninvolvesthebalancingofthecostsofinspectionagainsttheconsequencesofacceptinganundesirablenumberofnonconformingarticles.Thereisalwaysariskthatarandomsamplewillnotdescribecorrectlythecharacteristicsofthelotfromwhichitisdrawn,andthatanunacceptablelotwillbeacceptedoranacceptablelotwillberejected.Thelargerthesample,thesmallerthisriskbutthelargerthecostofinspection.Tounderstandtherisks,considerthatifeveryarticleinaninspectionlotconformstoitsrequirements,everyarticleinthesamplewillconformalso.Suchlotswillbeaccepted(Note1).Ifonlyafewarticlesinaninspectionlotarenonconforming,thesampleprobablywillindicatethatthelotisacceptable;butthereisasmallprobabilitythatthesamplewillindicatethatthelotisunacceptable.Thelargertheproportionofnonconformingarticlesinaninspectionlot,themorelikelyitwillbethatthesamplewillindicatethatthelotisunacceptable.Ifeveryarticleinaninspectionlotisnonconforming,asamplewillalwaysindicatethatthelotisunacceptable.Note18212;Throughoutthismethod,itisassumedthatnomistakesaremadeinsampling,measurement,andcalculation.The.......
【中国标准分类号】:A29
【国际标准分类号】:25_220_99
【页数】:10P.;A4
【正文语种】:英语