Designation:C1789−14StandardTestMethodforCalibrationofHand-HeldMoistureMetersonGypsumPanels1ThisstandardisissuedunderthefixeddesignationC1789;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodappliestothecalibrationofhandheldmoisturemetersforgypsumboard,glassfacedgypsumpanelsandfiber-reinforcedgypsumpanelsbymeansofelectricalconductanceanddielectricmeters.Thetestuseswettedtestspecimenswhicharedrieddowninatleast5stepstodeterminethemoisturecontentbasedontheweightlossincomparisontothedryweight.ThetestalsosuppliestheERHvaluesforeachofthedryingsteps.1.2Thistestmethodhasnotbeenevaluatedfortheinflu-enceofpaintorwallcoveringmaterialsontheindicatedmoisturecontentofagypsumboardorpanelsubstrate.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2C473TestMethodsforPhysicalTestingofGypsumPanelProductsC1177SpecificationforGlassMatGypsumSubstrateforUseasSheathingC1178SpecificationforCoatedGlassMatWater-ResistantGypsumBackingPanelC1278SpecificationforFiber-ReinforcedGypsumPanelC1396SpecificationforGypsumBoardD4442TestMethodsforDirectMoistureContentMeasure-mentofWoodandWood-BaseMaterialsD4444TestMethodforLaboratoryStandardizationandCalibrationofHand-HeldMoistureMeters2.2ASHRAEStandard:32009ASHRAEHandbook–Fundamentals,Chapter1–Psychrometrics,AmericanSocietyofHeating,Refrigerat-ingandAir-conditioningEngineers3.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1absolutehumidity,dv,n—theratioofthemassofwatervaportothetotalvolumeofthemoistairsample.3.1.2admittance,n—inverseofimpedance,ameasureofhoweasilyanelectriccurrent...
