Designation:D5543−15StandardTestMethodforLow-LevelDissolvedOxygeninWater1ThisstandardisissuedunderthefixeddesignationD5543;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoverstherapiddeterminationoflow-level(<100µg/L)dissolvedoxygeninthermal-cyclesteamcondensate,deaeratedboilerfeedwater,boilerwater,anddeaerateddeionizedwater.Colorcomparatorsallowtheesti-mationofconcentrationsrangingfrom0to100µg/L(ppb)oxygen.1.2Thistestmethodmaybeapplicabletoelectronic-grade,pharmaceutical-grade,andotherhigh-puritywaters,althoughthesewerenotaddressedinthecollaborativestudy.1.3Itistheuser’sresponsibilitytoensurethevalidityofthistestmethodforwatersofuntestedmatrices.1.4ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1066PracticeforSamplingSteamD1129TerminologyRelatingtoWaterD1193SpecificationforReagentWaterD2777PracticeforDeterminationofPrecisionandBiasofApplicableTestMethodsofCommitteeD19onWaterD3370PracticesforSamplingWaterfromClosedConduitsD5463GuideforUseofTestKitstoMeasureInorganicConstituentsinWater3.Terminology3.1Definitions—Fordefinitionsoftermsusedinthistestmethod,refertoTerminologyD1129.4.SummaryofTestMethod4.1Thetipofapartiallyevacuatedsealedampouleisbrokenwhilesubmergedinaflowingwatersample.Thesampleisdrawnintotheampoulewhereitreactsinstanta-neouslywiththeoxygen-sensitiveindicator(leucoformofRhodazineD)toproduceareddishvioletcolorwhoseintensityisproportionaltotheconcentrationofdissolvedoxygen.35.Significanc...
