Designation:E1477−98a(Reapproved2017)StandardTestMethodforLuminousReflectanceFactorofAcousticalMaterialsbyUseofIntegrating-SphereReflectometers1ThisstandardisissuedunderthefixeddesignationE1477;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthemeasurementofthelumi-nousreflectancefactorofacousticalmaterialsforuseinpredictingthelevelsofroomillumination.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.1.3Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2E284TerminologyofAppearanceE308PracticeforComputingtheColorsofObjectsbyUsingtheCIESystemE1164PracticeforObtainingSpectrometricDataforObject-ColorEvaluationE1264ClassificationforAcousticalCeilingProductsE1331TestMethodforReflectanceFactorandColorbySpectrophotometryUsingHemisphericalGeometryE1345PracticeforReducingtheEffectofVariabilityofColorMeasurementbyUseofMultipleMeasurementsE1347TestMethodforColorandColor-DifferenceMea-surementbyTristimulusColorimetry3.Terminology3.1Definitions:3.1.1DefinitionsofappearancetermsinTerminologyE284areapplicabletothistestmethod.3.1.2integratingsphere,n—anopticaldeviceusedeithertocollectfluxreflectedortransmittedfromaspecimenintoahemisphereortoprovideisotropicirradiationofaspecimenfromacompletehemisphere,consistingofanapproximatelysphericalcavitywithapertures(ports)foradmittinganddetectingflux...