pdf文档ASTM G155-05a(General)

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Designation:G155–05aStandardPracticeforOperatingXenonArcLightApparatusforExposureofNon-MetallicMaterials1ThisstandardisissuedunderthefixeddesignationG155;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoversthebasicprinciplesandoperatingproceduresforusingxenonarclightandwaterapparatusintendedtoreproducetheweatheringeffectsthatoccurwhenmaterialsareexposedtosunlight(eitherdirectorthroughwindowglass)andmoistureasrainordewinactualuse.Thispracticeislimitedtotheproceduresforobtaining,measuring,andcontrollingconditionsofexposure.Anumberofexposureproceduresarelistedinanappendix;however,thispracticedoesnotspecifytheexposureconditionsbestsuitedforthematerialtobetested.NOTE1—PracticeG151describesperformancecriteriaforallexposuredevicesthatuselaboratorylightsources.ThispracticereplacesPracticeG26,whichdescribesveryspecificdesignsfordevicesusedforxenon-arcexposures.TheapparatusdescribedinPracticeG26iscoveredbythispractice.1.2Testspecimensareexposedtofilteredxenonarclightundercontrolledenvironmentalconditions.Differenttypesofxenonarclightsourcesanddifferentfiltercombinationsaredescribed.1.3SpecimenpreparationandevaluationoftheresultsarecoveredinASTMmethodsorspecificationsforspecificmaterials.GeneralguidanceisgiveninPracticeG151andISO4892-1.Morespecificinformationaboutmethodsfordeter-miningthechangeinpropertiesafterexposureandreportingtheseresultsisdescribedinPracticeD5870.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.1.5.1Shouldanyozonebegeneratedfromtheoperationofthelamp(s),itshallbecarriedawayfromthetestspecimensandoperatingpersonnelbyanexhaustsystem.1.6ThispracticeistechnicallysimilartothefollowingISOdocuments:ISO4892-2,ISO11341,ISO105B02,ISO105B04,ISO105B05,andISO105B06.2.ReferencedDocuments2.1ASTMStandards:2D3980PracticeforInterlaboratoryTestingofPaintandRelatedMaterialsD5870PracticeforCalculatingPropertyRetentionIndexofPlasticsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethodG26PracticeforOperatingLight-ExposureApparatus(Xenon-ArcType)WithandWithoutWaterforExposureofNonmetallicMaterialsG113TerminologyRelatingtoNaturalandArtificialWeatheringTestsforNonmetallicMaterialsG151PracticeforExposingNonmetallicMaterialsinAc-celeratedTestDevicesThatUseLaboratoryLightSources2.2CIEStandards:CIE-Publ.No.85:RecommendationsfortheIntegratedIrradianceandtheSpectralDistributionofSimulatedSolarRadiationforTestingPurposes32.3InternationalStandardsOrganizationStandards:ISO1134,PaintandVarnishes—ArtificialWeatheringEx-posuretoArtificialRadiationtoFilteredXenonArcRadiation4ISO105B02,Textiles—TestsforColorfastness—PartB02ColorfastnesstoArtificialLight:XenonArcFadingLampTest4ISO105B04,Textiles—TestsforColorfastness—PartB04ColorfastnesstoArtificialWeathering:XenonArcFadingLampTest4ISO105B05,Textiles—TestsforColorfastness—PartB051ThispracticeisunderthejurisdictionofASTMCommitteeG03onWeatheringandDurabilityandisthedirectresponsibilityofSubcommitteeG03.03onSimulatedandControlledExposureTests.CurrenteditionapprovedOct.1,2005.PublishedNovember2005.Originallyapprovedin1997.Lastpreviouseditionapprovedin2005asG155–05.2ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.3AvailablefromAmericanNationalStandardsInstitute,11W.42dSt.,13thFloor,NewYork,NY10036).4AvailablefromAmericanNationalStandardsInstitute(ANSI),25W.43rdSt.,4thFloor,NewYork,NY10036.1Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.CopyrightbyASTMInt'l(allrightsreserved);ReproductionauthorizedperLicenseAgreementwithASTMInternational;WedJul508:55:42EDT2006DetectionandAssessmentofPhotochromism4ISO105B06,Textiles—TestsforColorfastness—PartB06ColorfastnesstoArtificialLightatHighTemperatures:XenonArcFadingLampTest4ISO4892-1,Plastics—MethodsofExposuretoLaboratoryLightSources,Part1,GeneralGuidance4ISO4892-2,Plastics—MethodsofExposuretoLaboratoryLightSources,Part2,Xenon-ArcSources42.4SocietyofAutomotiveEngineers’Standards:SAEJ1885,AcceleratedExposureofAutomotiveInteriorTrimComponentsUsingaControlledIrradianceWaterCooledXenonArcApparatus5SAEJ1960,AcceleratedExposureofAutomotiveExteriorMaterialsUsingaControlledIrradianceWaterCooledXenonArcApparatus5SAEJ2412,AcceleratedExposureofAutomotiveInteriorTrimComponentsUsingaControlledIrradianceXenon-ArcApparatus5SAEJ2527AcceleratedExposureofAutomotiveExteriorMaterialsUsingaControlledIrradianceXenon-ArcAp-paratus53.Terminology3.1Definitions—ThedefinitionsgiveninTerminologyG113areapplicabletothispractice.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1Asusedinthispractice,thetermsunlightisidenticaltothetermsdaylightandsolarirradiance,globalastheyaredefinedinTerminologyG113.4.SummaryofPractice4.1Specimensareexposedtorepetitivecyclesoflightandmoistureundercontrolledenvironmentalconditions.4.1.1Moistureisusuallyproducedbysprayingthetestspecimenwithdemineralized/deionizedwaterorbycondensa-tionofwatervaporontothespecimen.4.2Theexposureconditionmaybevariedbyselectionof:4.2.1Lampfilter(s),4.2.2Thelamp’sirradiancelevel,4.2.3Thetypeofmoistureexposure,4.2.4Thetimingofthelightandmoistureexposure,4.2.5Thetemperatureoflightexposure,4.2.6Thetemperatureofmoistureexposure,and4.2.7Thetimingofalight/darkcycle.4.3Comparisonofresultsobtainedfromspecimensexposedinthesamemodelofapparatusshouldnotbemadeunlessreproducibilityhasbeenestablishedamongdevicesforthematerialtobetested.4.4Comparisonofresultsobtainedfromspecimensexposedindifferentmodelsofapparatusshouldnotbemadeunlesscorrelationhasbeenestablishedamongdevicesforthematerialtobetested.5.SignificanceandUse5.1Theuseofthisapparatusisintendedtoinducepropertychangesassociatedwiththeenduseconditions,includingtheeffectsofsunlight,moisture,andheat.Theseexposuresmayincludeameanstointroducemoisturetothetestspecimen.Exposuresarenotintendedtosimulatethedeteriorationcausedbylocalizedweatherphenomena,suchasatmosphericpollu-tion,biologicalattack,andsaltwaterexposure.Alternatively,theexposuremaysimulatetheeffectsofsunlightthroughwindowglass.Typically,theseexposureswouldincludemois-tureintheformofhumidity.NOTE2—Caution:RefertoPracticeG151forfullcautionaryguidanceapplicabletoalllaboratoryweatheringdevices.5.2Variationinresultsmaybeexpectedwhenoperatingconditionsarevariedwithintheacceptedlimitsofthispractice.Therefore,noreferenceshallbemadetoresultsfromtheuseofthispracticeunlessaccompaniedbyareportdetailingthespecificoperatingconditionsinconformancewiththeReportSection.5.2.1Itisrecommendedthatasimilarmaterialofknownperformance(acontrol)beexposedsimultaneouslywiththetestspecimentoprovideastandardforcomparativepurposes.Itisrecommendedthatatleastthreereplicatesofeachmaterialevaluatedbeexposedineachtesttoallowforstatisticalevaluationofresults.6.Apparatus6.1LaboratoryLightSource—Thelightsourceshallbeoneormorequartzjacketedxenonarclampswhichemitradiationfrombelow270nmintheultravioletthroughthevisiblespectrumandintotheinfrared.Inorderforxenonarcstosimulateterrestrialdaylight,filtersmustbeusedtoremoveshortwavelengthUVradiation.Filterstoreduceirradianceatwavelengthsshorterthan310nmmustbeusedtosimulatedaylightfilteredthroughwindowglass.Inaddition,filterstoremoveinfraredradiationmaybeusedtopreventunrealisticheatingoftestspecimensthatcancausethermaldegradationnotexperiencedduringoutdoorexposures.6.1.1Thefollowingfactorscanaffectthespectralpowerdistributionoffilteredxenonarclightsourcesasusedintheseapparatus:6.1.1.1DifferencesinthecompositionandthicknessoffilterscanhavelargeeffectsontheamountofshortwavelengthUVradiationtransmitted.6.1.1.2Agingoffilterscanresultinchangesinfiltertransmission.Theagingpropertiesoffilterscanbeinfluencedbythecomposition.AgingoffilterscanresultinasignificantreductionintheshortwavelengthUVemissionofaxenonburner.6.1.1.3Accumulationofdepositsorotherresidueonfilterscaneffectfiltertransmission.6.1.1.4Agingofthexenonburneritselfcanresultinchangesinlampoutput.Changesinlampoutputmayalsobecausedbyaccumulationofdirtorotherresidueinorontheburnerenvelope.6.1.2Followthedevicemanufacturer’sinstructionsforrecommendedmaintenance.5AvailablefromSocietyofAutomotiveEngineers(SAE),400CommonwealthDr.,Warrendale,PA15096-0001.G155–05a2CopyrightbyASTMInt'l(allrightsreserved);ReproductionauthorizedperLicenseAgreementwithASTMInternational;WedJul508:55:42EDT20066.1.3SpectralIrradianceofXenonArcwithDaylightFilters—Filtersareusedtofilterxenonarclampemissionsinasimulationofterrestrialsunlight.Thespectralpowerdistri-butionofxenonarcswithneworpre-agedfilters6,7shallcomplywiththerequirementsspecifiedinTable1.6.1.4SpectralIrradianceofXenonArcWithWindowGlassFilters—Filtersareusedtofilterxenonarclampemissionsinasimulationofsunlightfilteredthroughwindowglass.8Table2showstherelativespectralpowerdistributionlimitsforxenonarcsfilteredwithwindowglassfilters.Thespectralpowerdistributionofxenonarcswithneworpre-agedfiltersshallcomplywiththerequirementsspecifiedinTable2.6.1.5SpectralIrradianceofXenonArcWithExtendedUVFilters—FilterthattransmitmoreshortwavelengthUVaresometimesusedtoacceleratetestresult.Althoughthistypeoffilterhasbeenspecifiedinsometests,theytransmitsignificantradiantenergybelow300nm(thetypicalcut-onwavelengthforterrestrialsunlight)andmayresultinagingprocessesnotoccurringoutdoors.ThespectralirradianceforaxenonarcwithextendedUVfiltersshallcomplywiththerequirementsofTable3.6.1.6Theactualirradianceatthetester’sspecimenplaneisafunctionofthenumberofxenonburnersused,thepowerappliedtoeach,andthedistancebetweenthetestspecimensandthexenonburner.Ifappropriate,reporttheirradianceandthebandpassinwhichitwasmeasured.6.2TestChamber—Thedesignofthetestchambermayvary,butitshouldbeconstructedfromcorrosionresistantmaterialand,inadditiontotheradiantsource,mayprovideformeansofcontrollingtemperatureandrelativehumidity.Whenrequired,provisionshallbemadeforthesprayingofwateronthetestspecimen,fortheformationofcondensateontheexposedfaceofthespecimenorfortheimmersionofthetestspecimeninwater.6.2.1Theradiationsource(s)shallbelocatedwithrespecttothespecimenssuchthattheirradianceatthespecimenfacecomplieswiththerequirementsinPracticeG151.6Ketola,W.,Skogland,T.,Fischer,R.,“EffectsofFilterandBurnerAgingontheSpectralPowerDistributionofXenonArcLamps,”DurabilityTestingofNon-MetallicMaterials,ASTMSTP1294,RobertHerling,Editor,ASTM,Philadelphia,1995.7Searle,N.D.,Giesecke,P.,Kinmonth,R.,andHirt,R.C.,“UltravioletSpectralDistributionsandAgingCharacteristicsofXenonArcsandFilters,”AppliedOptics,Vol.No.8,1964,pp.923–927.8Ketola,W.,Robbins,J.S.,“UVTransmissionofSingleStrengthWindowGlass,”AcceleratedandOutdoorDurabilityTestingofOrganicMaterials,ASTMSTP1202,WarrenD.KetolaandDouglasGrossman,Editors,ASTM,Philadelphia,1993.TABLE1RelativeUltravioletSpectralPowerDistributionSpecificationforXenonArcwithDaylightFiltersA,BSpectralBandpassWavelengthlinnmMinimumPercentCBenchmarkSolarRadiationPercentD,E,FMaximumPercentCl<2900.15290#l#3202.65.87.9320<l#36028.340.040.0360<l#40054.254.267.5ADatainTable1aretheirradianceinthegivenbandpassexpressedasapercentageofthetotalirradiancefrom290to400nm.ThemanufacturerisresponsiblefordeterminingconformancetoTable1.AnnexA1stateshowtodeterminerelativespectralirradiance.BThedatainTable1arebasedontherectangularintegrationof112spectralpowerdistributionsforwaterandaircooledxenon-arcswithdaylightfiltersofvariouslotsandages.Thespectralpowerdistributiondataisforfiltersandxenon-burnerswithintheagingrecommendationsofthedevicemanufacturer.Theminimumandmaximumdataareatleastthethreesigmalimitsfromthemeanforallmeasurements.CTheminimumandmaximumcolumnswillnotnecessarilysumto100%becausetheyrepresenttheminimumandmaximumforthedataused.Foranyindividualspectralpowerdistribution,thecalculatedpercentagefortheband-passesinTable1willsumto100%.Foranyindividualxenon-lampwithdaylightfilters,thecalculatedpercentageineachbandpassmustfallwithintheminimumandmaximumlimitsofTable1.Testresultscanbeexpectedtodifferbetweenexposuresusingxenonarcdevicesinwhichthespectralpowerdistributionsdifferbyasmuchasthatallowedbythetolerances.Contactthemanufacturerofthexenon-arcdevicesforspecificspectralpowerdistributiondataforthexenon-arcandfiltersused.DThebenchmarksolarradiationdataisdefinedinASTMG177andisforatmosphericconditionsandaltitudechosentomaximizethefractionofshortwavelengthsolarUV.Thisdataisprovidedforcomparisonpurposesonly.EPreviousversionsofthisstandardusedsolarradiationdatafromTable4ofCIEPublicationNumber85.SeeAppendixX4formoreinformationcomparingthesolarradiationdatausedinthisstandardwiththatforCIE85Table4.FForthebenchmarksolarspectrum,theUVirradiance(290to400nm)is9.8%andthevisibleirradiance(400to800nm)is90.2%expressedasapercentageofthetotalirradiancefrom290to800nm.ThepercentagesofUVandvisibleirradiancesonsamplesexposedinxenonarcdevicesmayvaryduetothenumberandreflectancepropertiesofspecimensbeingexposed.TABLE2RelativeUltravioletSpectralPowerDistributionSpecificationforXenon-ArcwithWindowGlassFiltersA,BSpectralBandpassWavelengthlinnmMinimumPercentCWindowGlassFilteredSolarRadiationPercentD,E,FMaximumPercentCl<3000.00.29300#l#3200.1#0.52.8320<l#36023.834.235.5360<l#40062.565.376.1ADatainTable2aretheirradianceinthegivenbandpassexpressedasapercentageofthetotalirradiancefrom300to400nm.ThemanufacturerisresponsiblefordeterminingconformancetoTable2.AnnexA1stateshowtodeterminerelativespectralirradiance.BThedatainTable2arebasedontherectangularintegrationof36spectralpowerdistributionsforwatercooledandaircooledxenon-arcswithwindowglassfiltersofvariouslotsandages.Thespectralpowerdistributiondataisforfiltersandxenon-burnerswithintheagingrecommendationsofthedevicemanufacturer.Theminimumandmaximumdataareatleastthethreesigmalimitsfromthemeanforallmeasurements.CTheminimumandmaximumcolumnswillnotnecessarilysumto100%becausetheyrepresenttheminimumandmaximumforthedataused.Foranyindividualspectralpowerdistribution,thecalculatedpercentagefortheband-passesinTable2willsumto100%.Foranyindividualxenon-lampwithwindowglassfilters,thecalculatedpercentageineachbandpassmustfallwithintheminimumandmaximumlimitsofTable2.Testresultscanbeexpectedtodifferbetweenexposuresusingxenonarcdevicesinwhichthespectralpowerdistribu-tionsdifferbyasmuchasthatallowedbythetolerances.Contactthemanufacturerofthexenon-arcdevicesforspecificspectralpowerdistributiondataforthexenon-arcandfiltersused.DThewindowglassfilteredsolardataisforasolarspectrumwithatmosphericconditionsandaltitudechosentomaximizethefractionofshortwavelengthsolarUV(definedinASTMG177)thathasbeenfilteredbywindowglass.TheglasstransmissionistheaverageforaseriesofsinglestrengthwindowglassestestedaspartofaresearchstudyforASTMSubcommitteeG3.02.8Whilethisdataisprovidedforcomparisonpurposesonly,itisdesirableforaxenon-arcwithwindowglassfilterstoprovideaspectrumthatisaclosematchtothiswindowglassfilteredsolarspectrum.EPreviousversionsofthisstandardusedwindowglassfilteredsolarradiationdatabasedonTable4ofCIEPublicationNumber85.SeeAppendixX4formoreinformationcomparingthesolarradiationdatausedinthestandardwiththatforCIE85Table4.FForthebenchmarkwindowglassfilteredsolarspectrum,theUVirradiance(300to400nm)is8.2%andthevisibleirradiance(400to800nm)is91.8%expressedasapercentageofthetotalirradiancefrom300to800nm.ThepercentagesofUVandvisibleirradiancesonsamplesexposedinxenonarcdeviceswithwindowglassfiltersmayvaryduetothenumberandreflectancepropertiesofspecimensbeingexposed,andtheUVtransmissionofthewindowglassfiltersused.G155–05a3CopyrightbyASTMInt'l(allrightsreserved);ReproductionauthorizedperLicenseAgreementwithASTMInternational;WedJul508:55:42EDT20066.3InstrumentCalibration—Toensurestandardizationandaccuracy,theinstrumentsassociatedwiththeexposureappa-ratus(thatis,timers,thermometers,wetbulbsensors,drybulbsensors,humiditysensors,UVsensors,radiometers)requireperiodiccalibrationtoensurerepeatabilityoftestresults.Wheneverpossible,calibrationshouldbetraceabletonationalorinternationalstandards.Calibrationscheduleandprocedureshouldbeinaccordancewithmanufacturer’sinstructions.6.4Radiometer—Theuseofaradiometertomonitorandcontroltheamountofradiantenergyreceivedatthespecimenisrecommended.Ifaradiometerisused,itshallcomplywiththerequirementsinPracticeASTMG151.6.5Thermometer—Eitherinsulatedorun-insulatedblackorwhitepanelthermometersmaybeused.ThermometersshallconformtothedescriptionsfoundinPracticeG151.Thetypeofthermometerused,themethodofmountingonspecimenholder,andtheexposuretemperatureshallbestatedinthetestreport.6.5.1Thethermometershallbemountedonthespecimenracksothatitssurfaceisinthesamerelativepositionandsubjectedtothesameinfluencesasthetestspecimens.6.5.2Somespecificationsmayrequirechamberairtempera-turecontrol.Positioningandcalibrationofchamberairtem-peraturesensorsshallbeinaccordancewiththedescriptionsfoundinPracticeG151.6.6Moisture—Thetestspecimensmaybeexposedtomois-tureintheformofwaterspray,condensation,immersion,orhighhumidity.6.6.1WaterSpray—Thetestchambermaybeequippedwithameanstointroduceintermittentwatersprayontothefrontorthebackofthetestspecimens,underspecifiedconditions.Thesprayshallbeuniformlydistributedoverthespecimens.Thespraysystemshallbemadefromcorrosionresistantmaterialsthatdonotcontaminatethewateremployed.6.6.1.1QualityofWaterforSpraysandImmersion—Spraywatermusthaveaconductivitybelow5µS/cm,containlessthan1-ppmsolids,andleavenoobservablestainsordepositsonthespecimens.Verylowlevelsofsilicainspraywatercancausesignificantdepositsonthesurfaceoftestspecimens.Careshouldbetakentokeepsilicalevelsbelow0.1ppm.Inadditiontodistillation,acombinationofdeionizationandreverseosmosiscaneffectivelyproducewateroftherequiredquality.ThepHofthewaterusedshouldbereported.SeePracticeG151fordetailedwaterqualityinstructions.6.6.1.2Condensation—Aspraysystemdesignedtocoolthespecimenbysprayingthebacksurfaceofthespecimenorspecimensubstratemayberequiredwhentheexposurepro-gramspecifiesperiodsofcondensation.6.6.2RelativeHumidity—Thetestchambermaybeequippedwithameanstomeasureandcontroltherelativehumidity.Suchinstrumentsshallbeshieldedfromthelampradiation.6.6.3WaterImmersion—Thetestchambermaybeequippedwithameanstoimmersespecimensinwaterunderspecifiedconditions.Theimmersionsystemshallbemadefromcorro-sionresistantmaterialsthatdonotcontaminatethewateremployed.6.7SpecimenHolders—Holdersfortestspecimensshallbemadefromcorrosionresistantmaterialsthatwillnotaffectthetestresults.Corrosionresistantalloysofaluminumorstainlesssteelhavebeenfoundacceptable.Brass,steel,orcoppershallnotbeusedinthevicinityofthetestspecimens.6.7.1Thespecimenholdersaretypically,butnotnecessar-ily,mountedonarevolvingcylindricalrackthatisrotatedaroundthelampsystemataspeeddependentonthetypeofequipmentandthatiscenteredbothhorizontallyandverticallywithrespecttotheexposurearea.6.7.2Specimenholdersmaybeintheformofanopenframe,leavingthebackofthespecimenexposed,ortheymayprovidethespecimenwithasolidbacking.Anybackingusedmayaffecttestresultsandshallbeagreeduponinadvancebetweentheinterestedparties.6.7.3Specimenholdersmayrotateontheirownaxis.Whentheseholdersareused,theymaybefilledwithspecimensplacedbacktoback.Rotationoftheholderonitsaxisalternatelyexposeseachspecimentodirectradiationfromthexenonburner.6.8ApparatustoAssessChangesinProperties—UsetheapparatusrequiredbytheASTMorotherstandardthatdescribesdeterminationofthepropertyorpropertiesbeingmonitored.7.TestSpecimen7.1RefertoPracticeG151.TABLE3RelativeUltravioletSpectralPowerDistributionSpecificationforXenonArcwithExtendedUVFiltersA,BSpectralBandpassWavelengthlinnmMinimumPercentCBenchmarkSolarRadiationPercentD,E,FMaximumPercentC250#l<2900.10.7290#l#3205.05.811.0320<l#36032.340.037.0360<l#40052.054.262.0ADatainTable3aretheirradianceinthegivenbandpassexpressedasapercentageofthetotalirradiancefrom250to400nm.ThemanufacturerisresponsiblefordeterminingconformancetoTable3.AnnexA1stateshowtodeterminerelativespectralirradiance.BThedatainTable3arebasedontherectangularintegrationof81spectralpowerdistributionsforwatercooledandaircooledxenon-arcswithextendedUVfiltersofvariouslotsandages.Thespectralpowerdistributiondataisforfiltersandxenon-burnerswithintheagingrecommendationsofthedevicemanufacturer.Theminimumandmaximumdataareatleastthethreesigmalimitsfromthemeanforallmeasurements.CTheminimumandmaximumcolumnswillnotnecessarilysumto100%becausetheyrepresenttheminimumandmaximumforthedataused.Foranyindividualspectralpowerdistribution,thecalculatedpercentagefortheband-passesinTable3willsumto100%.Foranyindividualxenon-arclampwithextendedUVfilters,thecalculatedpercentageineachbandpassmustfallwithintheminimumandmaximumlimitsofTable3.Testresultscanbeexpectedtodifferbetweenexposuresusingxenonarcdevicesinwhichthespectralpowerdistribu-tionsdifferbyasmuchasthatallowedbythetolerances.Contactthemanufacturerofthexenon-arcdevicesforspecificspectralpowerdistributiondataforthexenon-arcandfiltersused.DThebenchmarksolarradiationdataisdefinedinASTMG177andisforatmosphericconditionsandaltitudechosentomaximizethefractionofshortwavelenghtsolarUV.Thisdataisprovidedforcomparisonpurposesonly.EPreviousversionsofthisstandardusedsolarradiationdatafromTable4ofCIEPublicationNumber85.SeeAppendixX4formoreinformationcomparingthesolarradiationdatausedinthestandardwiththatforCIE85Table4.FForthebenchmarksolarspectrum,theUVirradiance(290to400nm)is9.8%andthevisibleirradiance(400to800nm)is90.2%expressedasapercentageofthetotalirradiancefrom290to800nm.ThepercentagesofUVandvisibleirradiancesonsamplesexposedinxenonarcdevicesmayvaryduetothenumberandreflectancepropertiesofspecimensbeingexposed.G155–05a4CopyrightbyASTMInt'l(allrightsreserved);ReproductionauthorizedperLicenseAgreementwithASTMInternational;WedJul508:55:42EDT20068.TestConditions8.1Anyexposureconditionsmaybeusedaslongastheexactconditionsaredetailedinthereport.AppendixX1listssomerepresentativeexposureconditions.Thesearenotneces-sarilypreferredandnorecommendationisimplied.Theseconditionsareprovidedforreferenceonly.9.Procedure9.1Identifyeachtestspecimenbysuitableindeliblemark-ing,butnotonareastobeusedintesting.9.2Determinewhichpropertyofthetestspecimenswillbeevaluated.Priortoexposingthespecimens,quantifytheappropriatepropertiesinaccordancewithrecognizedinterna-tionalstandards.Ifrequired(forexample,destructivetesting),useunexposedfilespecimenstoquantifytheproperty.SeePracticeD5870fordetailedguidance.9.3MountingofTestSpecimens—Attachthespecimenstothespecimenholdersintheequipmentinsuchamannerthatthespecimensarenotsubjecttoanyappliedstress.Toassureuniformexposureconditions,fillallofthespaces,usingblankpanelsofcorrosionresistantmaterialifnecessary.NOTE3—Evaluationofcolorandappearancechangesofexposedmaterialsmustbemadebasedoncomparisonstounexposedspecimensofthesamematerialwhichhavebeenstoredinthedark.Maskingorshieldingthefaceoftestspecimenswithanopaquecoverforthepurposeofshowingtheeffectsofexposureononepanelisnotrecommended.Misleadingresultsmaybeobtainedbythismethod,sincethemaskedportionofthespecimenisstillexposedtotemperatureandhumiditythatinmanycaseswillaffectresults.9.4ExposuretoTestConditions—Programtheselectedtestconditionstooperatecontinuouslythroughouttherequirednumberofrepetitivecycles.Maintaintheseconditionsthroughouttheexposure.Interruptionstoservicetheapparatusandtoinspectspecimensshallbeminimized.9.5SpecimenRepositioning—Periodicrepositioningofthespecimensduringexposureisnotnecessaryiftheirradianceatthepositionsfarthestfromthecenterofthespecimenareaisatleast90%ofthatmeasuredatthecenteroftheexposurearea.IrradianceuniformityshallbedeterminedinaccordancewithPracticeG151.9.5.1Ifirradianceatpositionsfarthestfromthecenteroftheexposureareaisbetween70and90%ofthatmeasuredatthecenter,oneofthefollowingthreetechniquesshallbeusedforspecimenplacement.9.5.1.1Periodicallyrepositionspecimensduringtheexpo-sureperiodtoensurethateachreceivesanequalamountofradiantexposure.Therepositioningscheduleshallbeagreeduponbyallinterestedparties.9.5.1.2Placespecimensonlyintheexposureareawheretheirradianceisatleast90%ofthemaximumirradiance.9.5.1.3Tocompensatefortestvariability,randomlypositionreplicatespecimenswithintheexposureareathatmeetstheirradianceuniformityrequirementsasdefinedinsection9.5.1.9.6Inspection—Ifitisnecessarytoremoveatestspecimenforperiodicinspection,takecarenottohandleordisturbthetestsurface.Afterinspection,thetestspecimenshallbereturnedtothetestchamberwithitstestsurfaceinthesameorientationaspreviouslytested.9.7ApparatusMaintenance—Thetestapparatusrequiresperiodicmaintenancetomaintainuniformexposureconditions.Performrequiredmaintenanceandcalibrationinaccordancewithmanufacturer’sinstructions.9.8Exposethetestspecimensforthespecifiedperiodofexposure.SeePracticeG151forfurtherguidance.9.9Attheendoftheexposure,quantifytheappropriatepropertiesinaccordancewithrecognizedinternationalstan-dardsandreporttheresultsinconformancewithPracticeG151.NOTE4—Periodsofexposureandevaluationoftestresultsaread-dressedinPracticeG151.10.Report10.1ThetestreportshallconformtoPracticeG151.11.PrecisionandBias11.1Precision:11.1.1Therepeatabilityandreproducibilityofresultsob-tainedinexposuresconductedaccordingtothispracticewillvarywiththematerialsbeingtested,thematerialpropertybeingmeasured,andthespecifictestconditionsandcyclesthatareused.Inround-robinstudiesconductedbySubcommitteeG03.03,the60°glossvaluesofreplicatePVCtapespecimensexposedindifferentlaboratoriesusingidenticaltestdevicesandexposurecyclesshowedsignificantvariability.Thevari-abilityshownintheseround-robinstudiesrestrictstheuseof“absolutespecifications”suchasrequiringaspecificpropertylevelafteraspecificexposureperiod.11.1.2Ifastandardorspecificationforgeneraluserequiresadefinitepropertylevelafteraspecifictimeorradiantexposureinanexposuretestconductedaccordingtothispractice,thespecifiedpropertylevelshallbebasedonresultsobtainedinaround-robinthattakesintoconsiderationthevariabilityduetotheexposureandthetestmethodusedtomeasurethepropertyofinterest.Theround-robinshallbeconductedaccordingtoPracticeE691orPracticeD3980andshallincludeastatisticallyrepresentativesampleofalllabo-ratoriesororganizationswhowouldnormallyconducttheexposureandpropertymeasurement.11.1.3Ifastandardorspecificationforusebetweentwoorthreepartiesrequiresadefinitepropertylevelafteraspecifictimeorradiantexposureinanexposuretestconductedaccord-ingtothispractice,thespecifiedpropertylevelshallbebasedonstatisticalanalysisofresultsfromatleasttwoseparate,independentexposuresineachlaboratory.Thedesignoftheexperimentusedtodeterminethespecificationshalltakeintoconsiderationthevariabilityduetotheexposureandthetestmethodusedtomeasurethepropertyofinterest.11.1.4Theround-robinstudiescitedin11.1.1demonstratedthattheglossvaluesforaseriesofmaterialscouldberankedwithahighlevelofreproducibilitybetweenlaboratories.Whenreproducibilityinresultsfromanexposuretestconductedaccordingtothispracticehavenotbeenestablishedthroughround-robintesting,performancerequirementsformaterialsshallbespecifiedintermsofcomparison(ranked)toacontrolmaterial.Thecontrolspecimensshallbeexposedsimulta-neouslywiththetestspecimen(s)inthesamedevice.ThespecificcontrolmaterialusedshallbeagreeduponbytheG155–05a5CopyrightbyASTMInt'l(allrightsreserved);ReproductionauthorizedperLicenseAgreementwithASTMInternational;WedJul508:55:42EDT2006

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