作者:标准资料网 时间:2024-04-29 01:45:59   浏览:9696   来源:标准资料网

【英文标准名称】:StandardPracticeforDeterminingtheActivationSpectrumofaMaterial(WavelengthSensitivitytoanExposureSource)UsingtheSharpCut-OnFilterorSpectrographicTechnique
【原文标准名称】:用锐截止-打开滤波器或光谱方法测定材料激活光谱(对辐照源的波长敏感性)的标准实施规程
【标准号】:ASTMG178-2009
【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】:activationspectrum;cumulativespectralsensitivitycurve;degradation;lightexposure;sharpcut-onfiltertechnique;spectrographictechnique;ultravioletradiation;Actinicradiation;Activationenergy;Lightexposure;Sharpcut-onfiltertechni
【摘要】:Theactivationspectrumidentifiesthespectralregion(s)ofthespecificexposuresourceusedthatmaybeprimarilyresponsibleforchangesinappearanceand/orphysicalpropertiesofthematerial.Thespectrographictechniqueusesaprismorgratingspectrographtodeterminetheeffectonthematerialofisolatednarrowspectralbandsofthelightsource,eachintheabsenceofotherwavelengths.Thesharpcut-onfiltertechniqueusesaspeciallydesignedsetofsharpcut-onUV/visibletransmittingglassfilterstodeterminetherelativeactiniceffectsofindividualspectralbandsofthelightsourceduringsimultaneousexposuretowavelengthslongerthanthespectralbandofinterest.Boththespectrographicandfiltertechniquesprovideactivationspectra,buttheydifferinseveralrespects:Thespectrographictechniquegenerallyprovidesbetterresolutionsinceitdeterminestheeffectsofnarrowerspectralportionsofthelightsourcethanthefiltertechnique.Thefiltertechniqueismorerepresentativeofthepolychromaticradiationtowhichsamplesarenormallyexposedwithdifferent,andsometimesantagonistic,photochemicalprocessesoftenoccurringsimultaneously.However,sincethefiltersonlytransmitwavelengthslongerthanthecut-onwavelengthofeachfilter,antagonisticprocessesbywavelengthsshorterthanthecut-onareeliminated.Inthefiltertechnique,separatespecimensareusedtodeterminetheeffectofthespectralbandsandthespecimensaresufficientlylargeformeasurementofbothmechanicalandopticalchanges.Inthespectrographictechnique,exceptinthecaseofspectrographsaslargeastheOkazakitype(1),asinglesmallspecimenisusedtodeterminetherelativeeffectsofallthespectralbands.Thus,propertychangesarelimitedtothosethatcanbemeasuredonverysmallsectionsofthespecimen.Theinformationprovidedbyactivationspectraonthespectralregionofthelightsourceresponsibleforthedegradationintheoryhasapplicationtostabilizationaswellastostabilitytestingofpolymericmaterials(2).Activationspectrabasedonexposureoftheunstabilizedmaterialtosolarradiationidentifythelightscreeningrequirementsandthusthetypeofultravioletabsorbertouseforoptimumscreeningprotection.ThecloserthematchoftheabsorptionspectrumofaUVabsorbertotheactivationspectrumofthematerial,themoreeffectivethescreening.However,agoodmatchoftheUVabsorptionspectrumoftheUVabsorbertotheactivationspectrumdoesnotnecessarilyassureadequateprotectionsinceitisnottheonlycriteriaforselectinganeffectiveUVabsorber.Factorssuchasdispersion,compatibility,migrationandotherscanhaveasignixFB01;cantinxFB02;uenceontheeffectivenessofaUVabsorber(seeNote3).Theactivationspectrummustbedeterminedusingalightsourcethatsimulatesthespectralpowerdistributionoftheonetowhichthematerialwillbeexposedunderuseconditions.Note38212;InastudybyASTMG03.01,theactivationspectrumofacopolyesterbasedonexposuretoborosilicateglass-filteredxenonarcradiationpredictedthatUVabsorberAwouldbesuperiortoUVabsorberBinoutdoorusebecauseofstrongerabsorptionoftheharmfulwavelengthsofsolarsimulatedradiation.However,bothadditivesprotectedthecopolyestertothesameextentwhenexposedeithertoxenonarcradiationoroutdoors.Comparisonoftheactivationspectrumofthestabilizedwiththatoftheunstabilizedmaterialprovidesinformationonthecompletenessofscreeningandidentifiesanyspectralregionsthatarenotadequatelyscreened.Comparisonoftheactivationspectrumof.........
【中国标准分类号】:G04
【国际标准分类号】:71_040_50
【页数】:12P.;A4
【正文语种】:英语