Designation:D6698−14StandardTestMethodforOn-LineMeasurementofTurbidityBelow5NTUinWater1ThisstandardisissuedunderthefixeddesignationD6698;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodisapplicabletotheon-linemeasure-mentofturbidityunder5nephelometricturbidityunits(NTU)inwater.1.2Itistheuser’sresponsibilitytoensurethevalidityofthistestmethodforwatersofuntestedmatrices.1.3InthistestmethodcalibrationstandardsaredefinedinNTUvalues,butotherassignedturbidityunitsareassumedtobeequivalent.1.4Thistestmethodassignstraceablereportingunitstothetypeofrespectivetechnologythatwasusedtoperformthemeasurement.Unitsarenumericallyequivalentwithrespecttothecalibrationstandard.Forexample,a1NTUformazinstandardisalsoequaltoa1FNU(formazinnephelometricunits)standard,a1FNRU(formazinnephelometricratiounits)standard,andsoforth.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1129TerminologyRelatingtoWaterD1193SpecificationforReagentWaterD2777PracticeforDeterminationofPrecisionandBiasofApplicableTestMethodsofCommitteeD19onWaterD3370PracticesforSamplingWaterfromClosedConduitsD3864GuideforOn-LineMonitoringSystemsforWaterAnalysisD7315TestMethodforDeterminationofTurbidityAbove1TurbidityUnit(TU)inStaticMode2.2OtherStandards:EPA180.1MethodsforChemicalAnalysisofWaterandWastes,Turbidity3GLIMethod24HachMethod8195DeterminationofTurbiditybyNephelo-metryEMMCFormat4ISO7027DeterminationofTurbidity5StandardMethod2130B62.3OtherDocuments:U.S.Paten...
