Designation:D5795−95(Reapproved2008)StandardTestMethodforDeterminationofLiquidWaterAbsorptionofCoatedHardboardandOtherCompositeWoodProductsVia“CobbRing”Apparatus1ThisstandardisissuedunderthefixeddesignationD5795;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodisintendedtoserveasameansformeasurementofliquidwaterthatpassesthroughawettedpaintfilm,andwhichissubsequentlyabsorbedandretainedbytheunderlyingwoodsubstrate.Alternativetechniquesfortheuseofthe“CobbRing”apparatusaredescribed.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterE177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethodsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod3.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1Cobbunit(C.U.),n—Theweightofdistilledwaterabsorbedbytheunderlyingwoodsubstrateingramsper645cm2(100in.2)ofsurfacearea(discountingadditionalareascontributedbytexturingorgrooves)per24-htimeperiod.3.1.2Cobbunit(C.U.)factor,n—adimensionlessmath-ematicaltermwhich,foragivenringsize,maybemultipliedtimestheweightchangeafter24htocalculatetheCobbunitvalue.3.1.2.1Discussion—TheC.U.factoriscalculatedasfol-lows:C.U.Factor5100Area~ring!5100pr2(1)where:r=radiusForexample,for101.6-mm(4-in.)insidediameterring.orC.U.Factor51003.14~2!2510012.5657.96(2)3.1.3compositewoodproducts,n—boardsorotherstruc-turedordecorativematerialsmanufacturedfromwoodfibers,flakesor...
