Designation:D2983−22StandardTestMethodforLow-TemperatureViscosityofAutomaticTransmissionFluids,HydraulicFluids,andLubricantsusingaRotationalViscometer1ThisstandardisissuedunderthefixeddesignationD2983;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope*1.1Thistestmethodcoverstheuseofrotationalviscom-eterswithanappropriatetorquerangeandspecificspindleforthedeterminationofthelow-shear-rateviscosityofautomatictransmissionfluids,gearoils,hydraulicfluids,andsomelubricants.Thistestmethodcoverstheviscosityrangeof300mPa·sto900000mPa·s1.2Thistestmethodwaspreviouslytitled“Low-TemperatureViscosityofLubricantsMeasuredbyBrookfieldViscometer.”Inthelubricantindustry,D2983testresultshaveoftenbeenreferredtoas“Brookfield2Viscosity”whichimpliesaviscositydeterminedbythismethod.1.3Thistestmethodcontainsfourprocedures:ProcedureAisusedwhenonlyanairbathisusedtocoolsamplesinpreparationforviscositymeasurement.ProcedureBisusedwhenamechanicallyrefrigeratedprogrammableliquidbathisusedtocoolsamplesinpreparationforviscositymeasurement.ProcedureCisusedwhenamechanicallyrefrigeratedconstanttemperatureliquidbathisusedtocoolsamplesbymeansofasimulatedaircell(SimAir)3Cellinpreparationforviscositymeasurement.ProcedureDautomatesthedeterminationoflowtemperature,low-shear-rateviscositybyutilizingathermo-electricallyheatedandcooledtemperature-controlledsamplechamberalongwithaprogrammablerotationalviscometer.1.4Therearemultipleprecisionstudiesforthistestmethod.1.4.1TheviscositydatausedfortheprecisionstudiesforProceduresA,B,andCcoveredarangefrom300mPa·sto170000mPa·sattesttemperaturesof–12°C,–26°C,and–40°C.AppendixX5includesprecisiondatafor–55°Ctesttemperatureandincludessampleswithviscositiesgreater500000mPa·s....
