1、Designation: D6194 10D6194 14Standard Test Method forGlow-Wire Ignition of Materials1This standard is issued under the fixed designation D6194; 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
2、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 covers the minimum temperature required to ignite insulating materials using a glowing heat source. Ina preliminary fashion, th
3、is test method differentiates between the susceptibilities of different materials with respect to theirresistance to ignition due to an electrically-heated source.1.2 This test method applies to molded or sheet materials available in thicknesses ranging from 0.25 to 6.4 mm.1.3 This test method is no
4、t valid for determining the ignition behavior of complete electrotechnical equipment, since the designof the electrotechnical product influences the heat transfer between adjacent parts.1.4 This test method measures and describes the response or materials, products, or assemblies to heat and flame u
5、ndercontrolled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials,products, or assemblies under actual fire conditions.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are include
6、d in this standard.(See IEEE/ASTM SI-10 for further details.)1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicab
7、ility of regulatorylimitations prior to use. For specific precautionary statements, see Section 9.1.7 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting thesetests.NOTE 1Although this test method and IEC 60695-2-13 differ in approach
8、and in detail, data obtained using either are technically equivalent.2. Referenced Documents2.1 ASTM Standards:2D1711 Terminology Relating to Electrical InsulationE176 Terminology of Fire StandardsE220 Test Method for Calibration of Thermocouples By Comparison TechniquesE230 Specification and Temper
9、ature-Electromotive Force (EMF) Tables for Standardized ThermocouplesIEEE/ASTM SI-10 International System of Units (SI), The Modernized Metric System2.2 IEC Standard:IEC 60695-4 Fire Hazard TestingPart 4: Terminology Concerning Fire Tests3IEC 60695-2-12 Fire Hazard TestingPart 212: Glowing/Hot-Wire
10、Based Test MethodsGlow-Wire Flammability TestMethod for Materials3IEC 60695-2-13 Fire Hazard TestingSection 20: Glowing/Hot-Wire Based Test MethodsGlow-Wire Coil Ignitability TestMethod for Materials32.3 ISO Standard:4ISO 13943 Fire SafetyVocabulary1 This test method is under the jurisdiction of AST
11、M Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of SubcommitteeD09.21 on Fire Performance Standards.Current edition approved March 1, 2010Nov. 1, 2014. Published April 2010November 2014. Originally approved in 1997. Last previous edition approved in
12、 20082010as D6194D6194 10.08. DOI: 10.1520/D6194-10.10.1520/D6194-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM
13、website.3 Available from International Electrotechnical Commission (IEC), 3 rueRue de Varemb, Case postale 131, CH-1211, Geneva 20, Switzerland, http:/www.iec.ch.4 Use undyed, soft, strong, lightweight tissue paper weighing between 12 and 30 30 g g/mm2.This document is not an ASTM standard and is in
14、tended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the cur
15、rent versionof the standard as published by ASTM is to be considered the official document.*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 States13. Terminology3.1 Definitions:
16、 DefinitionsUse Terminology E176, ISO 13943, and IEC 60695-4 for definitions of terms used in this testmethod and associated with fire issues. Where differences exist in definitions, those contained in Terminology E176 shall be used.Use Terminology D1711 for definitions of terms used in this test me
17、thod and associated with electrical insulation materials.3.2 Definitions of Terms Specific to This Standard:3.2.1 glow wire, glow-wire, na wire of specified dimensions that can be controllably-heated controllably heated electricallyto determine ignitability of a material.3.2.1.1 DiscussionFig. 1 sho
18、ws a glow wire glow-wire and its positioning.3.2.2 glow-wire flammability index (GWFI), nthe highest test temperature, during three subsequent tests for a test specimenof a given thickness, at which one of the following conditions are fulfilled: a) flames or glowing of the test specimen extinguishwi
19、thin 30 s after removal of the glow-wire and there is no ignition of the wrapping tissue placed underneath the test specimen;b) there is no ignition of the test specimen.3.2.3 glow-wire ignition temperature (GWIT), nthe temperature which is 25 C (30 C 25C (30C between 900 and 960 C)960C) higher than
20、 the GWFI.3.2.4 ignition, ninitiation of combustion.3.2.4.1 DiscussionIgnition is deemed to have taken place when the first of the following occurs: sustained flaming on the test specimen surface forover 5 s, or falling particles causing the appearance of flames on a tissue paper placed underneath t
21、he test specimen.NOTE 1All dimensions in millimetres.FIG. 1 Glow-Wire and Positioning of the ThermocoupleD6194 1424. Summary of Test Method4.1 In this test method, a standardized test specimen (either square or round), is supported vertically and is exposed to electricalheating from a glow-wire set
22、at pre-determined temperatures. The minimum temperature for glow-wire ignition is assessed throughtesting at incremental temperatures.5. Significance and Use5.1 During operation of electrical equipment, including wires, resistors, and other conductors, it is possible for overheating tooccur under ce
23、rtain conditions of operation, or when malfunctions occur. When this happens, a possible result is ignition of theadjacent insulation material.5.2 This test method assesses the susceptibility of electrical insulating materials to ignition as a result of exposure to a glowingwire.5.3 This test method
24、 determines the minimum temperature required to ignite a material by the effect of a glowing heat source,under the specified conditions of test.5.4 This method is suitable, subject to the appropriate limitations of an expected precision of 615 %, to categorize materials.5.5 In this procedure, the sp
25、ecimens are subjected to one or more specific sets of laboratory conditions. If different testconditions are substituted or the end-use conditions are changed, it is not always possible by or from this test to predict changesin the fire-test-response characteristics measured.Therefore, the results a
26、re valid only for the fire test exposure conditions describedin this procedure.6. Apparatus6.1 Glow-WireGlow-wireThe glow-wire shall be a Nichrome (Nickel-Chrome) wire,wire that is iron free, with thefollowing nominal properties: a wire composition of 20 % chromium-80 % nickel, a diameter of 4 mm, a
27、nd it shall be formed tothe dimensions shown in Fig. 1.6.2 ThermocoupleUse Type K sheathed fine-wire thermocouple, having an overall diameter of 1.0 mm max, and wiressuitable for continuous operation at temperatures up to 960 C, 960C, with the welded point located inside the sheath, formeasuring the
28、 temperature of the glow-wire. Examples of suitable wire compositions are Nickel-Chromium (NiCr) andNickel-Aluminum (NiAl).6.2.1 Construct the thermocouple sheath of a metal that will allow the thermocouple to perform its function in air at sheathtemperatures of at least 1050 C. 1050C.Arrange the th
29、ermocouple is arranged in a pocket hole, drilled in the tip of the glow-wire,as shown in Fig. 1. Maintain the thermal contact between the walls of the bored hole in the glow-wire by pinning the sheathedthermocouple in place. Ensure that the thermocouple follows the movement of the tip of the glow-wi
30、re resulting from elongationcaused by thermal heating.6.3 Temperature IndicatorUse a temperature indicator for Type K thermocouples capable of reading up to 1000 C. 1000C.Calibrate the combination thermocouple and temperature indicator in accordance with the general procedures outlined in TestMethod
31、 E220. The initial calibration tolerance is defined in the tables of Specification and Temperature-Electromotive Force(EMF) Tables E230.6.4 Supply CircuitThe supply circuit shall be capable of supplying up to 150 A at 2.1V,2.1 V, with smooth continuousadjustment of voltage to provide the required cu
32、rrent as needed to maintain the desired glow-wire tip temperature.6.5 Test FixtureAs shown in Fig. 2, the test fixture shall be capable of holding the glow-wire in a horizontal plane and movingit against the vertical test specimen, maintaining a force of 1.0 6 0.2 N over a distance of at least 7 mm.
33、NOTE 2A weight of 100 6 20 g, as shown in Fig. 2, will provide the required force.6.5.1 Use a weight of 100 6 20 g to provide the required force.6.6 Indicator BoardUse as indicator a flat pine wood board with a smooth finish, approximately 10 mm thick, and in closecontact with a single layer of tiss
34、ue paper,4 located at a distance of 200 6 5 mm below the glow-wire tip.6.7 Test ChamberUse as a test chamber a closed draft-free chamber that permits observation of the specimen and has a volumeof at least 0.3 m3. The test chamber shall be positively vented to the outside of the test facility before
35、 and after the test, but it shallremain closed and unvented during the test. The chamber shall be equipped with an observation window.7. Test Specimen7.1 Prepare square specimens that are approximately 60 60 mm or round specimens that are approximately 60 mm in diameter,and of a thickness commonly e
36、ncountered in practice. Thicknesses less than 0.25 mm or greater than 6.4 mm are not valid for thistest method. Generally, ten specimens will suffice to complete the procedure specified in Section 9.D6194 1438. Conditioning8.1 Condition specimens, test board and tissue paper at 23 6 2 C 2C and 50 6
37、5 % relative humidity for at least 40 h priorto testing.9. Safety Precautions9.1 It is possible that fumes and products of incomplete combustion are liberated from the specimen when conducting this test.Avoid the inhalation of such fumes and products of combustion and exhaust them from the test cham
38、ber after each run.9.2 Take precautions to safeguard the health of personnel against the risk of explosion or fire, the inhalation of smoke,smokeor other products of combustion, or the exposure to the residues potentially remaining on the specimen after testing.10. Procedure10.1 Before each test, cl
39、ean the tip of the glow-wire with a wire brush to remove any residue left from previously testedmaterials.10.2 Mount the specimen in the test fixture so that the surface that comes in contact with the tip of the glow-wire is verticaland any heat losses to the supporting means are insignificant. Adju
40、st the equipment so the depth of penetration is limited to 7 mmbelow the surface of the specimen. Shield the specimen during the heating of the glow-wire.10.3 Close the chamber vents and doors, making the test chamber draft free, and heat the glow-wire to the pre-determinedtemperature. Use the calib
41、rated thermocouple to record the glow-wire temperature. Maintain the pre-selected glow-wiretemperature for at least 60 s prior to conducting the test.10.4 Bring the specimen in contact with the tip of the glow-wire at an applied force of 1.0 6 0.2 N for 30 6 1 s.NOTE 2The glow-wire temperature will
42、decrease when the tip contacts the test specimen.10.5 Observe to see whether ignition occurs during the application of the glow-wire (see 3.2.1). For the purposes of this test,ignition will be deemed to have occurred if either sustained flaming occurs (appearance of a flame on the surface of the tes
43、tspecimen which lasts for more than 5 s) or the tissue paper on the indicator board placed underneath the apparatus exhibits flamescaused by particles falling from the test specimen.10.5.1 If ignition occurs, repeat the test with a new test specimen, and at a temperature 50 C 50C lower than that use
44、d duringthe previous test. If the resulting temperature has already been used, do not retest at that temperature.10.5.2 If ignition does not occur, repeat the test with a new test specimen, and at a temperature 50 higher than that used duringthe previous test. If the resulting temperature has alread
45、y been used, do not retest at that temperature.FIG. 2 Test Apparatus (Example)D6194 14410.6 When a maximum temperature has been determined, following the procedure in 10.5, repeat the test with a new testspecimen with a temperature interval of 25 C, 25C in the final approach, to determine the maximu
46、m test temperature which willnot cause ignition during three consecutive tests.10.7 The glow-wire ignition temperature is that temperature that is 25 C 25C higher than the highest temperature at whichthe tip of the glow-wire does not cause ignition during three consecutive tests.10.8 The glow-wire f
47、lammability index (GWFI) is the highest test temperature, during three subsequent tests for a test specimenof a given thickness, at which one of the following conditions are fulfilled:10.8.1 Flames or glowing of the test specimen extinguish within 30 s after removal of the glow wire glow-wire and th
48、ere is noignition of the wrapping tissue placed underneath the test specimen.10.8.2 There is no ignition of the test specimen.11. Report11.1 Report the following information:11.1.1 Complete identification of the material tested including type, source, and manufacturers code number,11.1.2 Thickness o
49、f specimens tested,11.1.3 The glow-wire ignition temperature, and11.1.4 The glow-wire flammability index.12. Precision and Bias12.1 PrecisionIt is not possible to specify the precision of the procedure in this test method for measuring the glow-wireignition temperature because insufficient data has been developed and compiled for a reliable statistical analysis.12.2 BiasNo information can be presented on the bias of the procedure in this test method for measuring the glow-wireignition temperature because no material havin
