Designation:D5671−20StandardPracticeforPolishingandEtchingCoalSamplesforMicroscopicalAnalysisbyReflectedLight1ThisstandardisissuedunderthefixeddesignationD5671;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoverslaboratoryproceduresforpreparinganetched,polishedsurfaceofgranularandblocksamplesofcoalforexaminationwithamicroscopeusingreflectedlightillumination.1.2Units—ThevaluesstatedinSIunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesafterSIunitsareprovidedforinformationonlyandarenotconsideredstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D121TerminologyofCoalandCokeD2797PracticeforPreparingCoalSamplesforMicroscopi-calAnalysisbyReflectedLightD2798TestMethodforMicroscopicalDeterminationoftheVitriniteReflectanceofCoalD2799TestMethodforMicroscopicalDeterminationoftheMaceralCompositionofCoalD4596PracticeforCollectionofChannelSamplesofCoalinaMineD5192PracticeforCollectionofCoalSamplesfromCore3.Terminology3.1TerminologyusedinthisstandardcanbefoundinTerminologyD121.4.SummaryofPractice4.1Asubsplitofarepresentativesampleobtainedinaccor-dancewithPracticeD4596andpreparedinaccordancewithPracticeD2797,orablockofcoalobtainedinaccordancewithPracticeD5192,ispolishedtoaflat,scratch-freesurface;thereflectanceo...
