Designation:D2798−11aStandardTestMethodforMicroscopicalDeterminationoftheVitriniteReflectanceofCoal1ThisstandardisissuedunderthefixeddesignationD2798;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthemicroscopicaldeterminationofboththemeanmaximumandmeanrandomreflectancesmeasuredinoilofpolishedsurfacesofvitriniteandothermaceralspresentincoalsranginginrankfromlignitetoanthracite.Thistestmethodcanbeusedtodeterminethereflectanceofothermacerals.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D121TerminologyofCoalandCokeD388ClassificationofCoalsbyRankD2797PracticeforPreparingCoalSamplesforMicroscopi-calAnalysisbyReflectedLight3.Terminology3.1Definitions—Fordefinitionsofterms,refertoTerminol-ogyD121.3.2Abbreviations:3.2.1Romax—meanmaximumreflectancemeasuredinoil.3.2.2Roran—meanrandomreflectancemeasuredinoil.3.2.2.1Discussion—Otherorganizationsmayuseotherab-breviationsformeanmaximumandmeanrandomreflectance.4.SummaryofTestMethod4.1Thereflectanceofthemaceralvitriniteorothermaceralsisdeterminedinthistestmethodbyilluminatingapolishedsurfaceofasectionofcoalinimmersionoilusingamicro-scopicsystemthatphotometricallymeasurestheamountoflightreflectedfromthesurface.Thereflectedlightisrecordedinpercentreflectanceaftercalibrationofphotometricequip-mentbymeasuringthereflectedlightfromstandardsofreflectanceascalculatedfromtheirrefractiveindices.5.SignificanceandUse5.1Themeanmaximumreflectanceofthevitrinitecompo-nen...
