Designation:D1218−12StandardTestMethodforRefractiveIndexandRefractiveDispersionofHydrocarbonLiquids1ThisstandardisissuedunderthefixeddesignationD1218;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope*1.1Thistestmethodcoversthemeasurementofrefractiveindex,accuratetofourdecimalplacesorbetter,oftransparentandlight-coloredhydrocarbonsintherangeof1.3300to1.5000attemperaturesfrom20to30°Cbymanual(optical-mechanical)orautomatic(digital)procedure.1.2Themanual(optical-mechanical)procedurealsocoversthemeasurementofrefractivedispersionaccuratetothefourthdecimalplaceorbetter.NOTE1—Thetestmethodmaybesuitableformeasuringtherefractiveindicesofliquidsabove1.5000andattemperaturesbothbelow20°Candabove30°C;however,thetestmethodprecisionmaynotapply.Verifica-tionoftheaccuracyofsuchmeasurementswilldependupontheavailabilityofreliable,certifiedreferencestandardsthatdemonstratetheperformanceoftheinstrumentusedundertheparticularmeasuringconditions.1.3Thetestmethodmaynotbeapplicabletoliquidsthatarestronglycolored,orthathavebubblepointssonearthetesttemperaturethatareadingcannotbeobtainedbeforesubstan-tialweatheringtakesplace.LiquidcolorshouldbelimitedtoNo.4ASTMColororlighter,asdeterminedbyTestMethodD1500.1.4ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.5WARNING—Mercuryhasbeendesignatedbymanyregulatoryagenciesasahazardousmaterialthatcancausecentralnervoussystem,kidneyandliverdamage.Mercury,oritsvapor,maybehazardoustohealthandcorrosivetomaterials.Cautionshouldbetakenwhenhandlingmercuryandmercurycontainingproducts.SeetheapplicableproductMa-terialSafetyDataSheet(MSDS)fordetailsandEPA’swebsite—http://www.epa.gov/mercury/faq.htm—foraddi-tionalinformation....
