1、Designation: F 2178 08Standard Test Method forDetermining the Arc Rating and Standard Specification forEye or Face Protective Products1This standard is issued under the fixed designation F 2178; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f 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. Scope1.1 This test method and product specification is used tomeasure the arc rating and specify the re
3、quirements forproducts intended for use as eye or face protection for workersexposed to electric arcs that would generate heat flux valuesfrom 84 to 25 120 kW/m22 to 600 cal/cm2s. Products aretested as sold.1.2 This test method determines an arc rating for eye or faceprotective products. The faceshi
4、eld, safety spectacle, goggle oror other applicable portions of the complete product must meetANSI Z87.1. This excludes the textile or non ANSI Z87.1testable parts of the hood assemblies or other tested products.This standard does not measure optical and impact properties(seeANSI Z87.1) but does spe
5、cify requirements for optical andimpact properties.1.3 The materials covered by this standard are in the form offaceshields attached to the head by protective helmets (hardhats), headgear, hood assemblies, safety spectacles or goggles.Faceshields, safety spectacles or goggles are tested with orwitho
6、ut other face and head protective products, for example,sock hoods, balaclavas, sweat shirt hoods or jacket hoods.1.3.1 Fabric layers used in hood assemblies or other itemstested under this standard shall meet the requirements ofSpecification F 1506.1.4 This test method shall be used to measure and
7、describethe properties of materials, products, or assemblies in responseto convective and radiant energy generated by an electric arcunder controlled laboratory conditions and does not purport topredict damage from light other than the thermal aspectsmeasured.1.5 The values stated in SI units shall
8、be regarded asstandard except as noted. Within the text, alternate units areshown in brackets. The values stated in each system may no beexact equivalents; therefore, alternate systems must be usedindependently of the other. Combining values from the systemsdescribed in the text may result in noncon
9、formance with themethod.1.6 This standard does not purport to describe or appraisethe effect of the electric arc fragmentation explosion andsubsequent molten metal splatter, which involves the pressurewave containing molten metals and possible fragments of othermaterials except to the extent that he
10、at energy transmission dueto these arc explosion phenomena is reduced by test specimens.1.7 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
11、 fire assessment which takes intoaccount all of the factors which are pertinent to an assessmentof the fire hazard of a particular end use.1.8 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
12、 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specificprecautions, see Section 7.2. Referenced Documents2.1 ASTM Standards:2C 177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Propertie
13、s by Means ofthe Guarded-Hot-Plate ApparatusD 123 Terminology Relating to TextilesD 3776 Test Methods for Mass Per Unit Area (Weight) ofFabricD 4391 Terminology Relating to The Burning Behavior ofTextilesE 457 Test Method for Measuring Heat-Transfer Rate Usinga Thermal Capacitance (Slug) Calorimeter
14、F 1494 Terminology Relating to Protective ClothingF 1506 Performance Specification for Flame Resistant Tex-tile Materials for Wearing Apparel for Use by ElectricalWorkers Exposed to Momentary Electric Arc and RelatedThermal HazardsF 1958/F 1958M Test Method for Determining the Ignit-ability of Non-f
15、lame-Resistant Materials for Clothing by1This 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 Sept. 15, 2008. Published October 2008. Originall
16、yapproved in 2002. Last previous edition approved in 2006 as F 2178 06.2For 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 AST
17、M website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Electric Arc Exposure Method Using MannequinsF 1959/F 1959M Test Method for Determining the ArcRating of Materials for Clothing2.2 ANSI/IEEE Standards:IEEE Standard Dictionary
18、 of Electrical and ElectronicsTerms3ANSI Z87.1-2003 Practice for Occupational and Educa-tional Eye and Face Protection43. Terminology3.1 DefinitionsFor definitions of other textile terms usedin this method, refer to terminology in Terminology D 123,D 4391, F 1494 and the IEEE Standard Dictionary of
19、Electricaland Electronics Terms.3.2 Definitions of Terms Specific to This Standard:3.2.1 afterflame, npersistent flaming of a material afterthe ignition source has been removed.3.2.2 afterflame time, nthe length of time for which amaterial continues to flame after the ignition source has beenremoved
20、.3.2.3 arc duration, ntime duration of the arc, s.3.2.4 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.3.2.5 arc gap, ndistance between the arc electrodes, cmin.3.2.6 arc rati
21、ng, nvalue attributed to materials that de-scribes their performance to exposure to an electric arcdischarge, J/cm2(cal/cm2).3.2.6.1 DiscussionThe arc rating is expressed inJ/cm2(cal/cm2) and is derived from the determined value ofATPV or EBT(should a material system exhibit a breakopenresponse belo
22、w the ATPV value).3.2.7 arc thermal performance value (ATPV), nin arctesting, the incident energy of a fabric or material that resultsin 50 % probability that sufficient heat transfer through thespecimen is predicted to cause the onset of a second-degreeskin burn injury based on the Stoll curve.53.2
23、.8 arc voltage, nvoltage across the gap caused by thecurrent flowing through the resistance created by the arc gap(V).3.2.9 asymmetrical arc current, nthe total arc currentproduced during closure; it includes a direct component and asymmetrical component, A.3.2.10 blowout, nthe extinguishing of the
24、arc caused by amagnetic field.3.2.11 breakopen, nin electric arc testing, a materialresponse evidenced by the formation of one or more holes inthe material which may allow thermal energy to pass throughmaterial.3.2.11.1 DiscussionThe specimen is considered to exhibitbreakopen when any hole in the ma
25、terial or fabric is at least 1.6cm20.5 in.2 in area or at least 2.5 cm 1.0 in. in anydimension. For textile materials, single threads across theopening or hole do not reduce the size of the hole for thepurposes of this test method. In multiple layer specimens, ifsome of the layers are ignitable, bre
26、akopen occurs when theselayers are exposed.3.2.12 breakopen threshold energy (EBT), nthe incidentenergy on a fabric or material that results in a 50 % probabilityof breakopen.3.2.12.1 DiscussionThis is the value in J/cm2cal/cm2determined by use of logistic regression analysis representingthe energy
27、at which breakopen of the layer occurred.3.2.13 deformation, nfor electric arc testing of eye or faceprotective products, the sagging of material greater than 7.6 cm3 in. or melting in any manner that the faceshield/windowtouches any part of the body.3.2.14 delta peak temperature, ndifference betwee
28、n themaximum temperature and the initial temperature of the sensorduring the test, C.3.2.15 dripping, nin electric arc testing, a material re-sponse evidenced by flowing of a specimens material ofcomposition.3.2.15.1 DiscussionDripping is exhibited by either thefabric material or faceshield material
29、, or other parts of eye orface protective products.3.2.16 electric arc ignition, nin electric arc testing of eyeor face protective products, the initiation of combustion asrelated to electric arc exposure, a response that causes theignition of textile test specimen material which is accompaniedby he
30、at and light, and then subsequent burning for at least 5 s,and consumption of at least 25 % of the test specimen area.3.2.16.1 DiscussionFor multilayer specimens, consump-tion of the innermost FR layer must be at least 25 %.3.2.17 faceshield, na protective device commonly in-tended to shield the wea
31、rers face, or portions thereof, inaddition to the eyes, from certain hazards.3.2.18 heat attenuation factor, HAF, nin electric arctesting, the average of the percent of the incident energy that isblocked by a material.3.2.18.1 DiscussionIn arc testing of eye or face protectiveproducts, HAF (face) is
32、 based on the highest sensor readingamong the four head sensors for each head exposure. HAF(eye) is based on the highest sensor reading among the two eyesensors for each head exposure.3.2.19 heat flux, nthe thermal intensity indicated by theamount of energy transmitted per area and time W/m2cal/cm2s
33、.3.2.20 i2t, nsum of the instantaneous arc current valuessquared multiplied by the incremental time values during thearc, A2/s.3Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http:/www.ieee.org.4Available from Ame
34、rican National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Derived from Stoll,A. M., and Chianta, M.A., “Method and Rating System forEvaluations of Thermal Protection,” Aerospace Medicine , Vol 40, 1969, pp.1232-1238 and Stoll, A. M., and Chianta, M.
35、 A., “Heat Transfer through Fabrics asRelated to Thermal Injury,” TransactionsNew York Academy of Sciences, Vol 33(7), Nov. 1971, pp. 649-670.F21780823.2.21 incident energy monitoring sensors, nsensorsmounted on each side of each head, using calorimeters, notcovered by specimens, used to measure inc
36、ident energy.3.2.22 incident exposure energy (Ei), nin arc testing, thetotal incident energy delivered to monitor calorimeter sensorsas a result of the arc exposure, J/cm2cal/cm2.3.2.22.1 DiscussionIn an arc test exposure, incident ex-posure energy for a specimen is determined from the averageof the
37、 measured incident energy from the respective twomonitor sensors adjacent to the test specimen.3.2.23 material response, nmaterial response to an elec-tric arc is indicated by the following terms: breakopen, melting,dripping, deformation, afterflame time, shrinkage, and electricarc ignition.3.2.24 m
38、elting, nin arc testing, a material response evi-denced by softening of the material.3.2.25 peak arc current, nmaximum value of the AC arccurrent, A.3.2.26 RMS arc current, nroot mean square of theAC arccurrent, A.3.2.27 shrinkage, nin testing eye or face protective prod-ucts, a material response ev
39、idenced by reduction in specimensize.3.2.28 Stoll curve, nan empirical predicted second-degreeskin burn injury model, also commonly referred to as the StollResponse.3.2.29 time to delta peak temperature, nthe time frombeginning of the initiation of the arc to the time the delta peaktemperature is re
40、ached, s.3.2.30 X/R ratio, nthe ratio of system inductive reactanceto resistance. It is proportional to the L/R ratio of time constant,and is, therefore, indicative of the rate of decay of any DCoffset. A large X/R ratio corresponds to a large time constantand a slow rate of decay.4. Summary of Test
41、 Method4.1 This test method determines the heat transport responseacross a material, fabric, or fabric system when exposed to theheat energy from an electric arc. This heat transport response isassessed versus the Stoll curve, an approximate human tissuetolerance predictive model that projects the o
42、nset of a second-degree burn injury.4.1.1 Products are mounted on the standard mannequin headcontaining copper slug calorimeters inserted in the eyes,mouth, and chin positions. During this procedure, the amountof heat energy transferred by the specimen eye or faceprotective products is measured duri
43、ng and after exposure to anelectric arc.4.1.2 The thermal energy exposure and heat transport re-sponse of the test specimen(s) are measured with copper slugcalorimeters. The change in temperature versus time is used,along with the known thermo-physical properties of copper todetermine the respective
44、 thermal energies delivered to andthrough the specimen(s).4.2 This procedure incorporates incident energy monitoringsensors.4.3 Product and material performance for this procedure aredetermined by comparing the amount of thermal energygenerated by the arc flash on monitor sensors with the energytran
45、sferred by or through the test specimen(s) and measured bysensors on the mannequin head.4.4 Product and material responses shall be further de-scribed by recording the observed effects of the electric arcexposure on the specimens using the terms in the Reportsection.5. Significance and Use5.1 This t
46、est method is intended for the determination of thearc rating of a product/design, intended for use as eye or faceprotection for workers exposed to electric arcs.5.1.1 Because of the variability of the arc exposure, differ-ent heat transmission values may be observed at individualsensors. The result
47、s of each sensor are evaluated in accordancewith Section 12.5.2 This test method maintains the specimen in a static,vertical position and does not involve movement except thatresulting from the exposure.5.3 This test method specifies a standard set of exposureconditions. Different exposure condition
48、s may produce differ-ent results.5.4 This specification covers the minimum performancecriteria for arc resistance and other requirements for eye or faceprotective products used by workers who may be exposed tothermal hazards of momentary electric arcs or flame.5.5 The purchaser has the option to per
49、form or haveperformed any of these tests in order to verify the performanceof the eye or face protective product. Claims for failure to meetthe specification are subject to verification by the manufacturer.NOTE 1In addition to the standard set of exposure conditions, otherconditions representative of the expected hazard may be used and shall bereported should this data be cited.6. Apparatus6.1 General Arrangement for Determining Rating UsingSensor Heads and Monitor SensorsThe test apparatus shallconsist of supply bus, arc
