ASTM_F_2298_-_03_2009e1.pdf

Designation:F229803(Reapproved 2009)1Standard Test Methods forWater Vapor Diffusion Resistance and Air Flow Resistanceof Clothing Materials Using the Dynamic MoisturePermeation Cell1This standard is issued under the fixed designation F2298;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTEReapproved with editorial changes in February 2009.1.Scope1.1 This test method covers the measurement of the mois-ture vapor transport and gas flow properties of fabrics,membranes,and membrane laminates used for protectivematerials.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D737 Test Method for Air Permeability of Textile Fabrics2.2 Other Standards:ISO 11092 TextilesPhysiological EffectsMeasurementof Thermal and Water-Vapour Resistance Under Steady-State Conditions(Sweating Guarded-Hotplate Test)3JIS L 1099 Testing Methods for Water Vapour Permeabilityof Clothes33.Terminology3.1 Definitions:3.1.1 water vapor diffusion,nthe process by which watervapor molecules move from a region of high concentration toa region of low concentration.3.1.2 water vapor transmission rate,n the steady watervapor flow in unit time through unit area of a material,underspecific conditions of temperature and humidity at each sur-face.4.Summary of Test Methods4.1 The testing outlined in this standard consists of measur-ing the amount of water vapor transport across a specimen.Thewater vapor transport properties can be measured in a purediffusion mode and in a diffusion/convection mode.4.2 Two test methods are presented in this standard:4.2.1 Part A(Diffusion Test)The test is done under themaximum difference in relative humidity and zero pressuregradient across the specimen so that only the water vapordiffusion transport through the specimen is measured(Fig.1).4.2.2 Part B(Combined Convection/Diffusion Test)A se-ries of pressure gradients is applied in specified increments toforce air through the material(Fig.1).Thus,the test isconducted under a combined air pressure gradient and concen-tration gradient that allows examination of the interaction ofconvective and diffusive mass transfer across the specimen.This method is designed for use on relatively air-permeabletextile materials because for air-impermeable materials,theresults will be the same as the diffusion test alone.5.Significance and Use5.1 The water vapor transport properties of textile materialsare of considerable importance in determining the comfortproperties of clothing systems.Water vapor transport throughporous textiles may occur due to both diffusion(driven byvapor concentration differences)and convection(driven by gaspressure differences).5.2 For air permeable porous materials,a very small pres-sure gradient can produce large convective flows through thepores in the structure.In many standard water vapor perme-ability test methods,when used for materials with high airpermeability,slight variations in pressure gradient across aspecimen will greatly influence the measured water vaportransport properties.Therefore,the water vapor transport1These test methods are under the jurisdiction of ASTM Committee F23 onPersonal Protective Clothing and Equipment and are the direct responsibility ofSubcommittee F23.60 on Human Factors.Current edition approved Feb.1,2009.Published March 2009.Originallyapproved in 2003.Last previous edition approved in 2003 as F2298-03.DOI:10.1520/F2298-03R09E01.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Copyright by ASTM Intl(all rights reserved);Tue Feb 19 09:38:12 EST 2013Downloaded/printed byKrishna Gupta(Porous+Materials+Inc.)pursuant to License Agreement.No further reproductions authorized.properties of the porous and non-porous textile materialscannot be directly compared when the method has no provisionfor controlling the pressure gradient.This test method deter-mines the diffusion and convection properties from the sametest and generates data that allows direct comparison of theresults obtained between materials.FIG.1 Overview of the Test MethodsF2298 03(2009)