ASTM G151-2010 使非金属材料暴露于使用实验室光源的加速试验装置的标准实施规程

作者:标准资料网 时间:2024-05-04 14:03:44  浏览:9486   来源:标准资料网

【英文标准名称】:StandardPracticeforExposingNonmetallicMaterialsinAcceleratedTestDevicesthatUseLaboratoryLightSources
【原文标准名称】:使非金属材料暴露于使用实验室光源的加速试验装置的标准实施规程
【标准号】:ASTMG151-2010
【标准状态】:现行
【国别】:美国
【发布日期】:2010
【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】:G03.03
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:accelerated;durability;exposure;light;temperature;weathering;ultraviolet;UV-radiation;Durability;Laboratoryaging/weathering;Lightexposure;Acceleratedweathering;Lightfastness;Nonmetallicmaterials;Weathering
【摘要】:Significance:Whenconductingexposuresindevicesthatuselaboratorylightsources,itisimportanttoconsiderhowwelltheacceleratedtestconditionswillreproducepropertychangesandfailuremodesassociatedwithend-useenvironmentsforthematerialsbeingtested.Inaddition,itisessentialtoconsidertheeffectsofvariabilityinboththeacceleratedtestandoutdoorexposureswhensettingupexposureexperimentsandwheninterpretingtheresultsfromacceleratedexposuretests.Nolaboratoryexposuretestcanbespecifiedasatotalsimulationofactualuseconditionsinoutdoorenvironments.Resultsobtainedfromtheselaboratoryacceleratedexposurescanbeconsideredasrepresentativeofactualuseexposuresonlywhenthedegreeofrankcorrelationhasbeenestablishedforthespecificmaterialsbeingtestedandwhenthetypeofdegradationisthesame.TherelativedurabilityofmaterialsinactualuseconditionscanbeverydifferentindifferentlocationsbecauseofdifferencesinUVradiation,timeofwetness,relativehumidity,temperature,pollutants,andotherfactors.Therefore,evenifresultsfromaspecificexposuretestconductedaccordingtothispracticearefoundtobeusefulforcomparingtherelativedurabilityofmaterialsexposedinaparticularexteriorenvironment,itcannotbeassumedthattheywillbeusefulfordeterminingrelativedurabilityofthesamematerialsforadifferentenvironment.Eventhoughitisverytempting,calculationofanaccelerationfactorrelatingxhormegajoulesofradiantexposureinalaboratoryacceleratedtesttoymonthsoryearsofexteriorexposureisnotrecommended.Theseaccelerationfactorsarenotvalidforseveralreasons.Accelerationfactorsarematerialdependentandcanbesignificantlydifferentforeachmaterialandfordifferentformulationsofthesamematerial.Variabilityintherateofdegradationinbothactualuseandlaboratoryacceleratedexposuretestcanhaveasignificanteffectonthecalculatedaccelerationfactor.Accelerationfactorscalculatedbasedontheratioofirradiancebetweenalaboratorylightsourceandsolarradiation,evenwhenidenticalbandpassesareused,donottakeintoconsiderationtheeffectsonamaterialofirradiance,temperature,moisture,anddifferencesinspectralpowerdistributionbetweenthelaboratorylightsourceandsolarradiation.Note48212;Ifuseofanaccelerationfactorisdesiredinspiteofthewarningsgiveninthispractice,suchaccelerationfactorsforaparticularmaterialareonlyvalidiftheyarebasedondatafromasufficientnumberofseparateexteriorandlaboratoryacceleratedexposuressothatresultsusedtorelatetimestofailureineachexposurecanbeanalyzedusingstatisticalmethods.AnexampleofastatisticalanalysisusingmultiplelaboratoryandexteriorexposurestocalculateanaccelerationfactorisdescribedbyJ.A.Simms(1).Thereareanumberoffactorsthatmaydecreasethedegreeofcorrelationbetweenacceleratedtestsusinglaboratorylightsourcesandexteriorexposures.MorespecificinformationonhoweachfactormayalterstabilityrankingofmaterialsisgiveninAppendixX1.Differencesinthespectraldistributionbetweenthelaboratorylightsourceandsolarradiation.Lightintensitieshigherthanthoseexperiencedinactualuseconditions.Testconditionswherespecimensareexposedcontinuouslytolightwhenactualuseconditionsprovidealternateperiodsoflightanddark.Specimentemperatureshigherthanthoseinactualconditions.Exposureconditionsthatproduceunrealistict.......
【中国标准分类号】:A21
【国际标准分类号】:19_040
【页数】:15P.;A4
【正文语种】:英语