Designation:D2798−21StandardTestMethodforMicroscopicalDeterminationoftheVitriniteReflectanceofCoal1ThisstandardisissuedunderthefixeddesignationD2798;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthemicroscopicaldeterminationofboththemeanmaximumandmeanrandomreflectancesmeasuredinoilofpolishedsurfacesofvitriniteandothermaceralspresentincoalsranginginrankfromlignitetoanthracite.Thistestmethodcanbeusedtodeterminethereflectanceofothermacerals.1.2Units—ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D121TerminologyofCoalandCokeD388ClassificationofCoalsbyRankD2797/D2797MPracticeforPreparingCoalSamplesforMicroscopicalAnalysisbyReflectedLight3.Terminology3.1Definitions—Fordefinitionsofterms,refertoTerminol-ogyD121.3.2Abbreviations:3.2.1Romax—meanmaximumreflectancemeasuredinoil.3.2.2Roran—meanrandomreflectancemeasuredinoil.3.2.2.1Discussion—Otherorganizationsmayuseotherab-breviationsformeanmaximumandmeanrandomreflectance.4.SummaryofTestMethod4.1Thereflectanceofthemaceralvitriniteorothermaceralsisdeterminedinthistestmethodbyilluminatingapolishedsurfaceofasectionofcoalinimmersionoilusingamicro-scopicsystemthatp...
