Designation:D8294−21StandardPracticeforEstimatingpHtoVerifyStatusofAqueousSamples1ThisstandardisissuedunderthefixeddesignationD8294;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThispracticeprovidesinformationonverifyingthepHofaqueoussamplesbeforeanalysis.Thispracticeisnotintendedtobeusedfornon-aqueoussampleslikeoilorgrease.1.2ThispracticemayalsobeusedinadjustingpHofsamplesduringvariousanalyticalsteps.1.3Wide-rangepHpapers/stripsareusedforarapidindi-cationofpHtowithinabout1pHunit,andnarrow-rangepHpapers/stripsareusedtoindicatepHwithinabout0.5pHunits.1.4Insomeinstances,auniversalliquidindicatormaybeused.1.5Units—ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.6Thispracticeoffersasetofinstructionsforperformingoneormorespecificoperations.Thisdocumentcannotreplaceeducationorexperienceandshouldbeusedinconjunctionwithprofessionaljudgment.Notallaspectsofthispracticemaybeapplicableinallcircumstances.ThisASTMInternationalstandardisnotintendedtorepresentorreplacethestandardofcarebywhichtheadequacyofagivenprofessionalservicemustbejudged,norshouldthisdocumentbeappliedwithoutconsiderationofaproject’smanyuniqueaspects.Theword“Standard”inthetitlemeansonlythatthedocumenthasbeenapprovedthroughtheASTMconsensusprocess.1.7Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.8Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrgani...
