1、Designation:F77888(Reapproved 2014)Standard Methods forGas Flow Resistance Testing of Filtration Media1This standard is issued under the fixed designation F778;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision
2、.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 The flow resistance of any fabricated filter device willdepend on the flow resistance of the media used.1.2 This standard offers procedure
3、s sufficient to determinethe gas flow characteristics of flat specimens of media used inthe filtration process.The methods are extended to includepleated specimens and bulk media as well.1.3 In all cases,flow rates through the specimen aredetermined in accordance with procedures outlined in ASME“Flu
4、id Meters.”The test fluid is air.1.4 This standard may involve hazardous materials,operations,and equipment.This standard does not purport toaddress all of the safety problems associated with its use.It isthe responsibility of the user of this standard to establishappropriate safety and health pract
5、ices and determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D461 Test Methods for Felt(Withdrawn 2003)3D585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,and Related Product(Withdrawn 2010)3D645/D645M Test Meth
6、od for Thickness of Paper andPaperboard(Withdrawn 2010)3D685 Practice for Conditioning Paper and Paper Productsfor TestingD737 Test Method for Air Permeability of Textile FabricsD1776 Practice for Conditioning and Testing TextilesD1777 Test Method for Thickness of Textile MaterialsD2905 Practice for
7、 Statements on Number of Specimens forTextiles(Withdrawn 2008)3D3574 Test Methods for Flexible Cellular MaterialsSlab,Bonded,and Molded Urethane FoamsE105 Practice for Probability Sampling of MaterialsE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Cha
8、racteristic of aLot or Process2.2 ASME Document:“Fluid Meters,”Sixth Edition,197143.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 air density,mass per unit volume.3.1.2 air flow resistance,Ppressure drop or pressuredifferential across a test specimen of filter medium at aspecif
9、ied air face velocity or mass flow rate.3.1.3 constituted bulk mediathose types of filter mediaformed from bonded aggregates or discrete solid materials.3.1.4 edge leakageair flow that passes into or bypasses thetest specimen in geometric planes other than those intended forresistance measurement.3.
10、1.5 face area,A cross-sectional area perpendicular to airflow at the specimen test boundary.NOTE1If specimen inlet and exit face areas are different,“Inlet”or“Exit”shall be used to describe the face area in question.3.1.6 face velocity,V volumetric flow rate per unit facearea.NOTE2If specimen inlet
11、and exit face areas are different,“Inlet”or“Exit”shall be used to describe the face velocity in question.3.1.7 mass rate of flow,m mass transport of air per unittime through the test specimen.3.1.8 medium area,Amtotal area of filtration media ex-posed to air flow.NOTE3Medium area may be greater than
12、 face area due to pleating,folding,etc.3.1.9 medium velocity,Vmvolumetric flow rate per unitmedium area.3.1.10 normalized resistance,Pproduct of sigma andmeasured air flow resistance.1These methods are under the jurisdiction of ASTM Committee D22 on AirQuality and are the direct responsibility of Su
13、bcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved April 1,2014.Published May 2014.Originallyapproved in 1982.Last previous edition approved in 2007 as F778 88(2007).DOI:10.1520/F0778-88R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontac
14、t ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from American Society of Mechanical Engineers(
15、ASME),ASMEInternational Headquarters,Two Park Ave.,New York,NY 10016-5990,http:/www.asme.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.11 sigma,ratio of air density existing at test condi-tions to standard air density.Density at
16、 standard conditions istaken to be 0.075 lb/ft3(1.201 kg/m3).3.1.12 unconstituted bulk mediathose types of filter mediaformed from unbonded aggregates or discrete solid materials.3.1.13 volumetric rate of flow,Qair volume transport perunit time through the test specimen.4.Summary of Methods4.1 The testing outlined in this standard consists of measur-ing air-flow resistance(pressure drop)across a specimen ofknown geometry at one or more air-flow rates.Alternatively,the flow rate may be measured a