【英文标准名称】:StandardPracticeforSelectingandCharacterizingWeatheringReferenceMaterials
【原文标准名称】:风化标准物质的选择与表征的标准实施规程
【标准号】:ASTMG156-2009
【标准状态】:现行
【国别】:美国
【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】:G03.01
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:accelerated-aging;analysisofvariance;exposure;round-robin;weatheringreferencematerial;Acceleratedaging/testing;Consistency;Exposuretests;Referencematerials(RM);Round-robintesting;Variance;Weathering;Acceleratedaging/testing;Consiste
【摘要】:Weatheringreferencematerialsareusedinlaboratoryacceleratedexposureteststoverifyconsistencyamongtestsrunatdifferenttimesandindifferentlaboratories,usingthesameexposureconditions.Specificationsdefiningconsistencyofexposureconditionsarebasedonthepropertychangeofareferencematerialafteradefinedperiodoftime.Someweatheringreferencematerialsareusedtodefineperiodsofexposure.Specificationscallingforuseofthesematerialsrequirethematerialtobeexposeduntiladefinedchangeintheweatheringreferencematerialisachieved.Specificationsareusuallybasedonresultsforasinglelotoftheweatheringreferencematerial.Whenanewlotofthereferencematerialisintroduced,round-robinstudiesarenecessarytocomparethenewandoldlotsandtoestablishappropriatelimitsforexpectedperformanceofthenewlot.Note28212;AnexampleoftheuseofaclearpolystyrenereferencestandardforthispurposeisgiveninSAEJ1885andSAEJ1960.Note38212;Someweatheringreferencematerials(forexamplebluewools)arealsousedtodefineperiodsofexposure.Althoughnotspecificallycoveredbythisstandard,theproceduresdescribedforcharacterizingareferencematerialusedtomonitorconsistencyofexposuresarealsogenerallyapplicabletocharacterizingreferencematerialsusedtodefineperiodsofexposure.Itisimportanttotesttheconsistencyofexposureinthelaboratoryaccelerateddevicewithaweatheringreferencematerialthatrespondstothetestconditionssimilartothewaythetestmaterialsrespond.Therefore,theweatheringreferencematerialshouldbesensitivetothespectralregionofthelightsourcemainlyresponsibleforproducingdegradationinthetestmaterialstoprovidethemostmeaningfulevaluationofexposuretestconsistency.Theweatheringreferencematerialshouldalsoprovideinformationonconsistencyoftemperatureandhumidityconditionsifthelatterareimportantfactorsindegradationofthetestmaterials.Note48212;Materialhomogeneitycanalsobeanimportantfactorinselectionofaweatheringreferencematerial,particularlyifweatheringisinitiatedbytheradiationabsorbedbyimpuritiesasisthecaseinaliphatictypepolymersexposedtoradiationlongerthan300nm.Themeasurementofthecharacteristicpropertyofaweatheringreferencematerialcanbesubjecttoerrordependingontheinstrumentandtheprocedureusedtomeasuretheproperty.Itisimportanttodevelopmeasurementproceduresthatareclearandwhichminimizechancesforoperatormisinterpretation.Itisalsoimportanttodeterminethelevelofvariabilitycausedbymeasurementofthecharacteristicproperty.Whenareferencematerialisusedtomonitororspecifytheconsistencyofanexposuretest,itisimportantthatanyspecificationlimitsdefinedbychangesinthereferencematerialbebasedonasoundstatisticalanalysisofresultsfromaproperlydesignedround-robinexperiment.Thispracticeprovidesaprocedurewhichcanbefollowedtosetuptheround-robin,analyzeresults,andestablishreasonablelimitsofchangeinthecharacteristicpropertyofthereferencematerialthatcanbeusedinspecifications.Theresultsobtainedaccordingtothispracticearevalidonlyfortheexposurecycleusedfortheround-robinandcannotbeappliedtothesameweatheringreferencematerialusedinadifferentexposurecycle.Thechangeincharacteristicpropertyofareferencematerialmaybeaffectedbytheplacementofthereferencematerialintheexposuredevice.Thisisoftenduetovariationsinlightintensityandtemperaturewithintheallowedexposurearea.Randomplacementofreplicatespecim.........
【中国标准分类号】:A21
【国际标准分类号】:19_040
【页数】:4P.;A4
【正文语种】:英语