Designation:D737−04(Reapproved2012)StandardTestMethodforAirPermeabilityofTextileFabrics1ThisstandardisissuedunderthefixeddesignationD737;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope1.1Thistestmethodcoversthemeasurementoftheairpermeabilityoftextilefabrics.1.2Thistestmethodappliestomostfabricsincludingwovenfabrics,nonwovenfabrics,airbagfabrics,blankets,nappedfabrics,knittedfabrics,layeredfabrics,andpilefabrics.Thefabricsmaybeuntreated,heavilysized,coated,resin-treated,orotherwisetreated.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesstatedininch-poundunitsmaybeapproximate.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D123TerminologyRelatingtoTextilesD1776PracticeforConditioningandTestingTextilesD2904PracticeforInterlaboratoryTestingofaTextileTestMethodthatProducesNormallyDistributedData(With-drawn2008)3D2906PracticeforStatementsonPrecisionandBiasforTextiles(Withdrawn2008)3D4850TerminologyRelatingtoFabricsandFabricTestMethodsF778MethodsforGasFlowResistanceTestingofFiltrationMedia3.Terminology3.1Fordefinitionoftextiletermsusedinthistestmethod:airpermeability,andfabric,refertoTerminologyD4850.3.2Fordefinitionsofcross-machinedirection;machinedirectionandothertextiletermsusedinthistestmethod,refertoTerminologyD123.4.SummaryofTestMethod4.1Therateofairflowpassingperpendicularlythroughaknownareaoffabricisadjustedtoobtainaprescribedairpressuredifferentialbetweenthetwofabricsurfaces.Fromthisrateofairflow,theairpermeabilityofthefabricisdetermin...
