Designation:D6855−17StandardTestMethodforDeterminationofTurbidityBelow5NTUinStaticMode1ThisstandardisissuedunderthefixeddesignationD6855;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthestaticdeterminationofturbidityinwater(see4.1).1.2Thistestmethodisapplicabletothemeasurementofturbiditiesunder5.0nephelometricturbidityunits(NTU).1.3Thistestmethodwastestedonmunicipaldrinkingwater,ultra-purewater,andlowturbiditysamples.Itistheusersresponsibilitytoensurethevalidityofthistestmethodforwatersofuntestedmatrices.1.4ThistestmethodusescalibrationstandardsaredefinedinNTUvalues,butotherassignedturbidityunitsareassumedtobeequivalent.1.5Thistestmethodassignstraceablereportingunitstothetypeofrespectivetechnologythatwasusedtoperformthemeasurement.Unitsarenumericallyequivalentwithrespecttothecalibrationstandard.Forexample,a1.0NTUformazinstandardisalsoequaltoa1.0FNUstandard,a1.0FNRUstandard,andsoforth.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.RefertotheMSDSsforallchemicalsusedinthistestmethod.1.7Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1129TerminologyRelatingtoWaterD1192GuideforEquipmentforSamplingWaterandSteaminClosedConduits(Withdrawn2003)3D1193SpecificationforReagentWaterD2777PracticeforDeterminationofPrecisionandBiasofApplicableTestMethodsofCommitteeD1...
