Designation:D7821−12StandardTestMethodforFieldTestDeterminationofUreaConcentrationinDieselExhaustFluid(DEF)1ThisstandardisissuedunderthefixeddesignationD7821;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversatechniqueforfieldtestingtheconcentrationofaqueousurea-baseddieselexhaustfluid(DEF)prescribedforuseindieselenginesequippedwithselectivecatalyticreductiontechnologyandisnotintendedtocircum-ventorreplacethemoreaccuratedeterminationofureacontentbyrefractiveindexlaboratorymethod,describedinISO22241-2,AnnexC.1.2ThistestmethodisdesignedsolelyasaquantitativetesttodeterminetheconcentrationofureainDEFanddoesnotpurporttodeterminethequalityofDEFnortodetecttraceorothercontaminantstherein.BiuretcontentofDEFcreatesaknownbiasinthistestmethod.Seesection9.2.1fordetails.1.3Units—ThevaluesstatedinSIunitsaretoberegardedasthestandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ISOStandard:2ISO2224122241Dieselengines—NOxreductionagentAUS323.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1AmericanPetroleumInstitute(API),n—anonprofittradeassociationthatlicensesdieselexhaustfluid(DEF)marketerstousetheAPIDieselExhaustFluidCertificationMark.AmarketermaybelicensedtousetheAPIMarkifitsDEFisincompliancewiththemostrecentandapplicableeditionofISO22241.3.1.2dieselexhaustfluid,DEF,n—preparationofaqueousurea[(NH2)2CO],containing32.5%byweightoftechnicallypureureainhigh-puritywaterwithqualitycharacteristicsdefinedbyISO22241.3.1.3refractiveindex,n—fundamentalphysicalpropertyofasu...
