ASTM_F_1958_-_F_1958M_-_12.pdf

Designation:F1958/F1958M12Standard Test Method forDetermining the Ignitability of Non-flame-Resistant Materialsfor Clothing by Electric Arc Exposure Method UsingMannequins1This standard is issued under the fixed designation F1958/F1958M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is used to identify materials that areignitable and that can continue to burn when exposed to anelectric arc,and determines(a)the incident exposure energythat causes ignition,and(b)the probability of ignition.1.2 The specimens tested in this test method are materialsfabricated in the form of shirts.1.3 This test method shall be used to measure and describethe properties of materials,products,or assemblies in responseto convective and radiant energy generated by an electric arcunder controlled laboratory conditions.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 This standard shall not be used to describe or appraisethe fire hazard or fire risk of materials,products,or assembliesunder actual fire conditions.However,results of this test maybe used as elements of a fire assessment which takes intoaccount all of the factors which are pertinent to an assessmentof the fire hazard of a particular end use.1.6 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.1.7 For specific precautions,see Section 7.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD4391 Terminology Relating to The Burning Behavior ofTextilesF1494 Terminology Relating to Protective ClothingF1506 Performance Specification for Flame Resistant andArc Rated Textile Materials for Wearing Apparel for Useby Electrical Workers Exposed to Momentary ElectricArcand Related Thermal HazardsF1959/F1959M Test Method for Determining theArc Ratingof Materials for Clothing2.2 ANSI/IEEE Standards:3Standard Dictionary of Electrical and Electronics Terms33.Terminology3.1 Definitions:3.1.1 See also Terminology D4391.3.1.2 arc duration,ntime duration of the arc,s.3.1.3 arc energy,vi dt,nsum of the instantaneous arcvoltage values multiplied by the instantaneous arc currentvalues multiplied by the incremental time values during thearc,J.3.1.4 arc gap,ndistance between the arc electrodes,cmin.3.1.5 arc voltage,nvoltage across the gap caused by thecurrent flowing through the resistance created by the arc gap,V.3.1.6 asymmetrical arc current,nthe total arc currentproduced during closure;it includes a direct component and asymmetrical component,A.1This test method is under the jurisdiction of ASTM Committee F18 onElectrical Protective Equipment for Workers and is the direct responsibility ofSubcommittee F18.65 on Wearing Apparel.Current edition approved Oct.1,2012.Published November 2012.Originallyapproved in 1997 as PS 57 97.Last previous edition approved in 2010 asF1958/F1958M-99(2010).DOI:10.1520/F1958_F1958M-12.2For 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 the Institute of Electrical and Electronic Engineers,Inc.,345 E.47th St.,New York,NY 10017.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.7 blowout,nthe extinguishing of the arc caused by amagnetic field.3.1.8 closure,npoint on supply current wave form wherearc is initiated.3.1.9 heatflux,nthe thermal intensity indicated by theamount of energy transmitted per unit area and time(cal/cm2s)(W/cm2).3.1.10 i2t,nsum of the instantaneous arc current valuessquared multiplied by the incremental time values during thearc,A2/s.3.1.11 ignitability,n(ignitable,adj)in electric arcexposure,the property of a material involving ignition accom-panied by heat and light,and continued burning resulting inconsumption of at least 25%of the exposed area of the testspecimen.3.1.12 ignition,nthe initiation of combustion.3.1.13 incident energy(Ei),nthe amount of energy(totalheat,cal/cm2)received at a surface as a direct result of anelectrical arc discharge as measured by temperature rise oncopper calorimeters.3.1.14 incidentenergymonitoringsensorssensorsmounted on each side of the mannequins.3.1.14.1 DiscussionSensors us