Designation:D7946−14StandardTestMethodforInitialpH(i-pH)-ValueofPetroleumProducts1ThisstandardisissuedunderthefixeddesignationD7946;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversproceduresforthedetermina-tionofinitialpH(i-pH)innewandin-servicelubricants.NOTE1—Innewandusedoils,theconstituentsthatmaybeconsideredtohavecharacteristicsinfluencingthei-pHvalueincludeorganicandinorganicacids,esters,phenoliccompounds,lactones,resins,saltsofheavymetals,saltsofammoniaandotherweakbases,acidsaltsofpolybasicacids,andadditionagentssuchasinhibitorsanddetergents.“Initial”isusedtodifferentiatefromaqueoussystems.Theanalysisisterminatedafteradefinedtimeintervalwheneverequilibriumconditions,asknownforpHmeasurementsinaqueoussystems,arenotreached(see3.1.1.2)1.2Thistestmethodisusedtoindicaterelativechangesthatoccurinoilduringuseunderoxidizingconditionsorduetocontaminationbyblow-bygasesofcombustionprocessesofbiogasesregardlessofthecolororotherpropertiesofthein-servicelubricants.AlthoughtheinitialpHismadeunderdefiniteequilibriumconditions,thetestmethodisnotintendedtomeasureanabsoluteacidicpropertythatcanbeusedtopredictperformanceofoilunderserviceconditions.Nogeneralcorrelationbetweencorrosionofnon-ferrousbearingmetalsandinitialpHvalueisknown.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterD4057PracticeforManualSamplingofPetroleumandPetroleumProductsD4177PracticeforAutomaticSamplingofPe...
