1、Designation: F2178 12Standard Test Method forDetermining the Arc Rating and Standard Specification forEye or Face Protective Products1This standard is issued under the fixed designation F2178; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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 requ
3、irements 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 faceshiel
4、d, 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 speci
5、fy 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 orwithout
6、 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 F1506.1.4 This test method shall be used to measure and des
7、cribethe 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 be
8、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 nonconfor
9、mance 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 heat
10、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 fi
11、re 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 es
12、tablish 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:2C177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by
13、 Means ofthe Guarded-Hot-Plate ApparatusD123 Terminology Relating to TextilesD3776 Test Methods for Mass Per Unit Area (Weight) ofFabricD4391 Terminology Relating to The Burning Behavior ofTextilesE457 Test Method for Measuring Heat-Transfer Rate Usinga Thermal Capacitance (Slug) CalorimeterF1494 Te
14、rminology Relating to Protective ClothingF1506 Performance Specification for Flame Resistant andArc Rated Textile Materials for Wearing Apparel for Use1This test method is under the jurisdiction of ASTM Committee F18 onElectrical Protective Equipment for Workers and is the direct responsibility ofSu
15、bcommittee F18.65 on Wearing Apparel.Current edition approved Oct. 1, 2012. Published November 2012. Originallyapproved in 2002. Last previous edition approved in 2008 as F2178 08. DOI:10.1520/F2178-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Serv
16、ice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1by Electrical Workers Exposed to Momentary El
17、ectricArcand Related Thermal HazardsF1958/F1958M Test Method for Determining the Ignitabil-ity of Non-flame-Resistant Materials for Clothing byElectric Arc Exposure Method Using MannequinsF1959/F1959M Test Method for Determining theArc Ratingof Materials for Clothing2.2 ANSI/IEEE Standards:IEEE Stan
18、dard Dictionary 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 D123,D4391, F1494 and the IEEE Standard Di
19、ctionary of Electricaland Electronics Terms.3.2 Definitions of Terms Specific to This Standard:3.2.1 afterflame, npersistent flaming of a material after theignition source has been removed.3.2.2 afterflame time, nthe length of time for which amaterial continues to flame after the ignition source has
20、 beenremoved.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.
21、2.6 arc rating, 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 breakopenr
22、esponse below the ATPV value).3.2.7 arc thermal performance value (ATPV), nthe inci-dent energy of a fabric or material that results in 50 %probability that sufficient heat transfer through the specimen ispredicted to cause the onset of a second-degree skin burn injurybased on the Stoll curve, kW/m2
23、cal/cm2.53.2.8 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 extinguis
24、hing of the 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 ho
25、le in the material 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 ig
26、nitable, breakopen 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 representin
27、gthe energy 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 dripping, nin electric arc tes
28、ting, a material re-sponse evidenced by flowing of a specimens material ofcomposition.3.2.14.1 DiscussionDripping is exhibited by either thefabric material or faceshield material, or other parts of eye orface protective products.3.2.15 electric arc ignition, nin electric arc testing of eyeor face pr
29、otective products, the initiation of combustion asrelated to electric arc exposure, a response that causes theignition of textile test specimen material which is accompaniedby heat and light, and then subsequent burning for at least 5 s,and consumption of at least 25 % of the test specimen area.3.2.
30、15.1 DiscussionFor multilayer specimens, consump-tion of the innermost FR layer must be at least 25 %.3.2.16 faceshield, na protective device commonly in-tended to shield the wearers face, or portions thereof, inaddition to the eyes, from certain hazards.3.2.17 heat attenuation factor, HAF, nin elec
31、tric arctesting, the average of the percent of the incident energy that isblocked by a material.3.2.17.1 DiscussionIn arc testing of eye or face protectiveproducts, HAF (face) is based on the highest sensor readingamong the four head sensors for each head exposure. HAF(eye) is based on the highest s
32、ensor reading among the two eyesensors for each head exposure.3.2.18 heat flux, nthe thermal intensity indicated by theamount of energy transmitted per area and time W/m2cal/cm2s.3Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),445 Hoes Ln., P.O. Box 1331, Piscataway, N
33、J 08854-1331, http:/www.ieee.org.4Available from American 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,
34、1969, pp.1232-1238 and Stoll, A. M., and Chianta, M. A., “Heat Transfer through Fabrics asRelated to Thermal Injury,” TransactionsNew York Academy of Sciences, Vol 33(7), Nov. 1971, pp. 649-670.F2178 1223.2.19 i2t, nsum of the instantaneous arc current valuessquared multiplied by the incremental tim
35、e values during thearc, A2/s.3.2.20 incident energy monitoring sensors, nsensorsmounted on each side of each head, using calorimeters, notcovered by specimens, used to measure incident energy.3.2.21 incident exposure energy (Ei), nin arc testing, thetotal incident energy delivered to monitor calorim
36、eter sensorsas a result of the arc exposure, J/cm2cal/cm2.3.2.21.1 DiscussionIn an arc test exposure, incident ex-posure energy for a specimen is determined from the averageof the measured incident energy from the respective twomonitor sensors adjacent to the test specimen.3.2.22 material response,
37、nmaterial response to an elec-tric arc is indicated by the following terms: breakopen, melting,dripping, deformation, afterflame time, shrinkage, and electricarc ignition.3.2.23 melting, nin arc testing, a material response evi-denced by softening of the material.3.2.24 peak arc current, nmaximum va
38、lue of the AC arccurrent, A.3.2.25 RMS arc current, nroot mean square of the AC arccurrent, A.3.2.26 shrinkage, nin testing eye or face protectiveproducts, a material response evidenced by reduction inspecimen size.3.2.27 Stoll curve, nan empirical predicted second-degreeskin burn injury model, also
39、 commonly referred to as the StollResponse.3.2.28 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 slo
40、w rate of decay.4. Summary of Test 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 pr
41、edictive model that projects the onset 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 facepr
42、otective products is measured during 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
43、 copper todetermine the respective 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 m
44、onitor sensors with the energytransferred 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
45、.5. Significance and Use5.1 This test 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 observe
46、d at individualsensors. The results 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 exposurecondit
47、ions. Different exposure conditions 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 T
48、he purchaser has the option to perform 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
49、, 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 controller, recorder, arc electrodes,two (or optionally three) four-sensor heads, and four (oroptionally six) incident energy monitoring sensors. The arcexposure shall be monitored with two incident energy-monitoring sensors for each sensored head.6.1.1 Arrangement
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