Designation:G7/G7M−13StandardPracticeforAtmosphericEnvironmentalExposureTestingofNonmetallicMaterials1ThisstandardisissuedunderthefixeddesignationG7/G7M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thispracticecoversprocedurestobefollowedfordirectexposureofnonmetallicmaterialstotheenvironment.Whenoriginatorsofaweatheringtesthavetheactualexposureconductedbyaseparateagency,thespecificconditionsfortheexposureoftestandcontrolspecimensmustbeclearlydefinedandmutuallyagreeduponbetweenallparties.1.2Forexposuresbehindglass,refertoPracticeG24.1.3ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.4ThispracticeistechnicallyequivalenttothepartsofISO877thatdescribedirectexposuresofspecimenstotheenvironment.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2E41TerminologyRelatingToConditioningE824TestMethodforTransferofCalibrationFromRefer-encetoFieldRadiometersE913MethodforCalibrationofReferencePyranometersWithAxisVerticalbytheShadingMethod(Withdrawn2005)3E941TestMethodforCalibrationofReferencePyranom-etersWithAxisTiltedbytheShadingMethod(Withdrawn2005)3G24PracticeforConductingExposurestoDaylightFilteredThroughGlassG113TerminologyRelatingtoNaturalandArtificialWeath-eringTestsofNonmetallicMaterialsG130TestMethodforCalibrationofNarrow-andBroad-BandUltra...
