Designation:D1955–85(Reapproved1995)StandardTestMethodforGelTimeofDryingOils1ThisstandardisissuedunderthefixeddesignationD1955;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope1.1Thistestmethodcoversthedeterminationofthegeltimeoftungoil,oiticicaoil,and,withmodificationoftemperature,otheroilshavinggellingcharacteristics.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:E1SpecificationforASTMThermometers23.Terminology3.1Definition:3.1.1geltime,ofadryingoil—thetimerequiredfortheoiltoformasolidgelunderspecifiedconditionsoftemperature.4.SignificanceandUse4.1Thegeltimeofanoilatelevatedtemperatureisanindicationofitsdryingcharacteristics.Oilsthathaveahighdegreeofunsaturationareclassedasdryingoils.Oilsinwhichahighpercentageofthisunsaturationisconjugateddrythefastest.4.2Atelevatedtemperatures,theconjugatedoilswillformagel;thereforethistestmethodcanbeusedtodetectadulterationinhighlyconjugatedoilssuchastungandoiticicaoil,whereasunconjugatedoilsdonotshowasharpgelpoint.Themethodisempiricalinnaturesincethegeltimemustbecomparedtoaknownstandard.5.Apparatus5.1TheapparatusshallbeassembledasshowninFig.1andshallconsistofthefollowing:5.1.1Bath—A1000-mL,tall-formbeaker,containingahydrogenatedoilorothersuitableliquidtoadepthof110mm.ThebeakershallbecoveredwithaMonel,aluminum,orstainlesssteelsupportplatefortesttubesandthermometer.5.1.2GlassRods,approximately170mminlength.5.1.3TestTubes,150by16mmwithamarktodesignatethe5-mLlevel.Eachtubeshallbeclosedwithacorkhavingaholethroughwhicha3-m...
