ASTM C1549-2004 使用便携式太阳反射计测定接近室内温度太阳反射比的标准试验方法

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【英文标准名称】:StandardTestMethodforDeterminationofSolarReflectanceNearAmbientTemperatureUsingaPortableSolarReflectometer
【原文标准名称】:使用便携式太阳反射计测定接近室内温度太阳反射比的标准试验方法
【标准号】:ASTMC1549-2004
【标准状态】:现行
【国别】:
【发布日期】:2004
【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】:C16.30
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:便携的;反射率;反射计;接近;测定;环境温度
【英文主题词】:portablereflectometer;reflectometer;solarreflectance;solarreflectometer
【摘要】:Thetemperaturesofopaquesurfacesexposedtosolarradiationaregenerallyhigherthantheadjacentairtemperatures.Inthecaseofroofsorwallsenclosingconditionedspaces,increasedinwardheatflowsresult.Inthecaseofequipmentorstoragecontainersexposedtothesun,increasedoperatingtemperaturesusuallyresult.Theextenttowhichsolarradiationaffectssurfacetemperaturesdependsonthesolarreflectanceoftheexposedsurface.Asolarreflectanceof1.0(100%reflected)wouldmeannoeffectonsurfacetemperaturewhileasolarreflectanceof0(nonereflected,allabsorbed)wouldresultinthemaximumeffect.Coatingsofspecificsolarreflectanceareusedtochangethetemperatureofsurfacesexposedtosunlight.Coatingsandsurfacefinishesarecommonlyspecifiedintermsofsolarreflectance.Theinitial(clean)solarreflectancemustbemaintainedduringthelifeofthecoatingorfinishtohavetheexpectedthermalperformance.Thetestmethodprovidesameansforperiodictestingofsurfacesinthefieldorinthelaboratory.Monitorchangesinsolarreflectanceduetoagingandexposure,orboth,withthistestmethod.Thistestmethodisusedtomeasurethesolarreflectanceofaflatopaquesurface.Theprecisionoftheaverageofseveralmeasurementsisusuallygovernedbythevariabilityofreflectancesonthesurfacebeingtested.UsethesolarreflectancethatisdeterminedbythismethodtocalculatethesolarenergyabsorbedbyanopaquesurfaceasshowninEq1.5.4.1Combinetheabsorbedsolarenergywithconductive,convectiveandotherradiativetermstoconstructaheatbalancearoundanelementorcalculateaSolarReflectanceIndexsuchasthatdiscussedinPracticeE1980.1.1Thistestmethodcoversatechniquefordeterminingthesolarreflectanceofflatopaquematerialsinalaboratoryorinthefieldusingacommercialportablesolarreflectometer.Thepurposeofthetestmethodistoprovidesolarreflectancedatarequiredtoevaluatetemperaturesandheatflowsacrosssurfacesexposedtosolarradiation.1.2ThistestmethoddoesnotsupplantTestMethodE903whichmeasuressolarreflectanceoverthewavelengthrange250to2500nmusingintegratingspheres.Theportablesolarreflectometeriscalibratedusingspecimensofknownsolarreflectancetodeterminesolarreflectancefrommeasurementsatfourwavelengthsinthesolarspectrum:380nm,500nm,650nm,and1220nm.ThistechniqueissupportedbycomparisonofreflectometermeasurementswithmeasurementsobtainedusingTestMethodE903.Thistestmethodisapplicabletospecimensofmaterialshavingbothspecularanddiffuseopticalproperties.Itisparticularlysuitedtothemeasurementofthesolarreflectanceofopaquematerials.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesinparenthesisareforinformationonly.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:F12
【国际标准分类号】:27_160
【页数】:4P.;A4
【正文语种】: