ASTM_D_3874_-_20.pdf

Designation:D387420Standard Test Method forIgnition of Materials by Hot Wire Sources1This standard is issued under the fixed designation D3874;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.1.Scope*1.1 This test method is intended to differentiate,in apreliminary fashion,among materials with respect to theirresistance to ignition because of their proximity to electrically-heated wires and other heat sources.21.2 This test method applies to molded or sheet materialsavailable in thicknesses up to and including 13.0 mm(0.51 in.).1.3 This test method applies to materials that are rigid orflexible at normal room temperatures.It is important tominimize deformation during preparation,especially duringthe wire-wrapping step described in 10.1,by following themethod outlined under Clause 10,Sample Preparation.Ex-amples of deformation include bowing,in either a transverse ora longitudinal direction,twisting of the specimen,and inden-tation of the wire into the specimen during the wire-wrappingstep,to a degree visible to the eye.1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses after SI units areprovided for information only and are not considered standard.(See SI10 for further details.)1.5 This test method measures and describes the response ofmaterials,products,or assemblies to heat and flame undercontrolled conditions,but does not by itself incorporate allfactors required for fire hazard or fire risk assessment of thematerials,products,or assemblies under actual fire conditions.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 Fire testing is inherently hazardous.Adequate safe-guards for personnel and property shall be employed inconducting these tests.NOTE1Although this test method and IEC TS 60695-2-20(with-drawn)differ in approach and in detail,data obtained using either aretechnically equivalent.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D1711 Terminology Relating to Electrical InsulationD6194 Test Method for Glow-Wire Ignition of MaterialsE176 Terminology of Fire StandardsE3020 Practice for Ignition SourcesIEEE/ASTM SI-10 American National Standard for MetricPractice2.2 IEC Standards:4IEC TS 60695-2-20:2004 Fire Hazard TestingSection 20:Glowing/Hot-wire Based Test Methods,Hot-wire CoilIgnitability Test on Materials(withdrawn)IEC 60695-4 Fire Hazard TestingPart 4:TerminologyConcerning Fire Tests for Electrotechnical Products2.3 ISO Standard:5ISO 13943 Fire SafetyVocabulary3.Terminology3.1 Definitions:3.1.1 Use Terminology E176,ISO 13943,and IEC 60695-4for definitions of terms used in this test method and associatedwith fire issues.Where differences exist in definitions,thosecontained in Terminology E176 shall be used.Use Terminol-ogy D1711 for definitions of terms used in this test method andassociated with electrical insulation materials.1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.17 on Fire and Thermal Properties.Current edition approved March 1,2020.Published March 2020.Originallyapproved in 1988.Last previous edition approved in 2018 as D3874 18.DOI:10.1520/D3874-20.2Mathes,K.N.,“Surface Failure Measurements,”Engineering Dielectrics,Vol IIB,Electrical Properties of Solid Insulating Materials:MeasurementTechniques,ASTM STP 926,Chapter 4,ASTM International,1987.3For 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.4Available from International Electrotechnical Commission(IEC),3,rue deVaremb,1st floor,P.O.Box 131,CH-1211,Geneva 20,Switzerland,https:/www.iec.ch.5Available from International Organization for Standardization(ISO),ISOCentral Secretariat,BIBC II,Chemin de Blandonnet 8,CP 401,1214 Vernier,Geneva,Switzerland,http:/www.iso.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with inte