Designation:D2161−20StandardPracticeforConversionofKinematicViscositytoSayboltUniversalViscosityortoSayboltFurolViscosity1ThisstandardisissuedunderthefixeddesignationD2161;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope*1.1Thispractice2coverstheconversiontablesandequa-tionsforconvertingkinematicviscosityinmm2/satanytemperaturetoSayboltUniversalviscosityinSayboltUniver-salseconds(SUS)atthesametemperatureandforconvertingkinematicviscosityinmm2/sat122°Fand210°F(50°Cand98.9°C)toSayboltFurolviscosityinSayboltFurolseconds(SFS)atthesametemperatures.Kinematicviscosityvaluesarebasedonwaterbeing1.0034mm2/s(cSt)at68°F(20°C).1.2IfamethodotherthanTestMethodD445isusedtogeneratethekinematicviscositydata,applyappropriaterelative-biascorrectionfactorsasfoundintheprecisionsectionofthatmethod,beforeperformingthecalculationsofthispractice.NOTE1—TheequationsinD2161wereoriginallyempiricallyderivedusingdatafrombothD445andtheSayboltviscometermethod.Therefore,itisconceivablethatanerrorcouldresultifthekinematicviscositiesusedarenotbias-correctedtoD445results.Itisrecommendedthatkinematicviscositybereportedinmillimetressquaredpersecond,insteadofSayboltUniversalSeconds(SUS)orSayboltFurolSeconds(SFS).ThismethodisbeingretainedforthepurposeofcalculationofkinematicviscositiesfromSUSandSFSdatathatappearinpastliterature.Onemillimetresquaredpersecond(mm2/s)equalsonecentistoke(cSt),whichisanotherunitcommonlyfoundinolderliterature.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareprovidedforreferenceinformationpurposesonly.TheSIunitofkinematicviscosityismm2/s.1.3.1Exception—Fahrenheittemperatureunitsareusedinthispracticebecausetheyareacceptedbyindustryforthetypeoflegacycon...
