Designation:D6378−10StandardTestMethodforDeterminationofVaporPressure(VPX)ofPetroleumProducts,Hydrocarbons,andHydrocarbon-OxygenateMixtures(TripleExpansionMethod)1ThisstandardisissuedunderthefixeddesignationD6378;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoverstheuseofautomatedvaporpressureinstrumentstodeterminethevaporpressureexertedinvacuumbyvolatile,liquidpetroleumproducts,hydrocarbons,andhydrocarbon-oxygenatemixtures.Thistestmethodissuitablefortestingsampleswithboilingpointsabove0°C(32°F)thatexertavaporpressurebetween7and150kPa(1.0and21psi)at37.8°C(100°F)atavapor-to-liquidratioof4:1.Theliquidsamplevolumesizerequiredforanalysisisdepen-dentuponthevapor-to-liquidratiochosen(seeNote1)andthemeasuringchambervolumecapacityoftheinstrument(see6.1.1andNote3).NOTE1—Thetestmethodissuitableforthedeterminationofthevaporpressureofvolatile,liquidpetroleumproductsattemperaturesfrom0to100°Catvaportoliquidratiosof4:1to1:1(X=4to1)andpressuresupto500kPa(70psi),buttheprecisionstatement(seeSection16)maynotbeapplicable.1.2Thistestmethodalsocoverstheuseofautomatedvaporpressureinstrumentstodeterminethevaporpressureexertedinvacuumbyaviationturbinefuels.Thistestmethodissuitablefortestingaviationturbinefuelsampleswithboilingpointsabove0°C(32°F)thatexertavaporpressurebetween0and110kPa(0and15.5psi)atavapor-to-liquidratioof4:1,inthetemperaturerangefrom25to100°C(77to212°F).1.3Thevaporpressure(VPX)determinedbythistestmethodatavapor-liquidratioof4:1(X=4)ofgasolineandgasoline-oxygenateblendsat37.8°Ccanbecorrelatedtothedryvaporpressureequivalent(DVPE)valuedeterminedbyTestMethodD5191(see16.3).Thisconditiondoesnotapplywhenthesampleisaviationturbinefuel.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformatio...
