1、Designation: E2965 16a An American National StandardStandard Test Method forDetermination of Low Levels of Heat Release Rate forMaterials and Products Using an Oxygen ConsumptionCalorimeter1This standard is issued under the fixed designation E2965; the number immediately following the designation in
2、dicates 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 fire-test-response standard provid
3、es a procedure formeasuring the response of materials that emit low levels of heatrelease when exposed to controlled levels of radiant heatingwith or without an external igniter.1.2 This test method differs from Test Method E1354 in thatit prescribes a different specific test specimen size, specimen
4、holder, test specimen orientation, a direct connection betweenthe plenum and the top plate of the cone heater assembly toensure complete collection of all the combustion gases (Fig. 1),and a lower volumetric flow rate for analyses via oxygenconsumption calorimetry. It is intended for use on material
5、sand products that contain only small amounts of combustibleingredients or components, such as test specimens that yield apeak heat release of 200 kWm2and total heat release of15 MJm2.NOTE 1PMMA is typically used to check the general operation of aCone Calorimeter. PMMA should not be used with this
6、standard as theheat release rate is too high.1.3 The rate of heat release is determined by measurementof the oxygen consumption as determined by the oxygenconcentration and the flow rate in the exhaust product stream.The effective heat of combustion is determined from a con-comitant measurement of t
7、est specimen mass loss rate, incombination with the heat release rate. Smoke development (anoptional measurement) is measured by obscuration of light bythe combustion product stream.1.4 Test specimens shall be exposed to initial test heat fluxesgenerated by a conical radiant heater. External ignitio
8、n, whenused, shall be by electric spark. The test specimen testingorientation is horizontal, independent of whether the end-useapplication involves a horizontal or a vertical orientation.1.5 Ignitability is determined as a measurement of timefrom initial exposure to time of sustained flaming.1.6 Thi
9、s test method has been developed for use for materialand product evaluations, mathematical modeling, designpurposes, and development and research. Examples of materialtest specimens include portions of an end-use product or thevarious components used in the end-use product.1.7 The values stated in S
10、I units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.8 This standard is used to measure and describe theresponse of materials, products, or assemblies to heat andflame under controlled conditions, but does not by itselfincorporate all factors required f
11、or fire hazard or fire riskassessment of the materials, products, or assemblies underactual fire conditions.1.9 Fire testing is inherently hazardous. Adequate safe-guards for personnel and property shall be employed inconducting these tests.1.10 This standard does not purport to address all of thesa
12、fety 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. For specific hazardstatements, see Section 7.2. Referenced Documents2.1
13、ASTM Standards:D5865 Test Method for Gross Calorific Value of Coal andCokeE176 Terminology of Fire StandardsE603 Guide for Room Fire ExperimentsE906 Test Method for Heat and Visible Smoke ReleaseRates for Materials and Products Using a ThermopileMethodE1354 Test Method for Heat and Visible Smoke Rel
14、easeRates for Materials and Products Using an Oxygen Con-sumption Calorimeter2.2 ISO StandardsISO 5657-1986 (E) Fire TestsReaction to FireIgnitability of Building MaterialsISO 5725-2 (1994) Accuracy (Trueness and Precision) ofMeasurement Methods and ResultsPart 2: Basic1This test method is under the
15、 jurisdiction of ASTM Committee E05 on FireStandards and is the direct responsibility of Subcommittee E05.23 on Combustibil-ity.Current edition approved Sept. 1, 2016. Published November 2016. Originallyapproved in 2015. Last previous edition approved in 2016 as E2965-16. DOI:10.1520/E2965-16A.*A Su
16、mmary 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 States1Method for the Determination of Repeatability and Re-producibility of a Standard Measurement Method3. Terminology3.1 Definitio
17、nsFor definitions of terms used in this testmethod, refer to Terminology E176.3.2 Definitions of Terms Specific to This Standard:3.2.1 effective heat of combustion, nthe amount of heatgenerated per unit mass lost by a material, product or assembly,when exposed to specific fire test conditions (contr
18、ast grossheat of combustion).3.2.1.1 DiscussionThe effective heat of combustion de-pends on the test method, and is determined by dividing themeasured heat release by the mass loss during a specifiedperiod of time under the specified test conditions. Typically, thespecified fire test conditions are
19、provided by the specificationsof the fire test standard that cites effective heat of combustionas a quantity to be measured. For certain fire test conditions,involving very high heat and high oxygen concentrations underhigh pressure, the effective heat of combustion will approxi-mate the gross heat
20、of combustion. More often, the fire testconditions will represent or approximate certain real fireexposure conditions, and the effective heat of combustion is theappropriate measure. Typical units are kJ/g or MJ/kg.3.2.2 gross heat of combustion, nthe maximum amount ofheat per unit mass that theoret
21、ically can be released by thecombustion of a material, product, or assembly; it can bedetermined experimentally and only under conditions of highpressure and in pure oxygen (contrast effective heat of com-bustion).3.2.3 heat flux, nheat transfer to a surface per unit area,per unit time (see also ini
22、tial test heat flux).3.2.3.1 DiscussionThe heat flux from an energy source,such as a radiant heater, can be measured at the initiation of atest (such as Test Method E1354 or Test Method E906) andthen reported as the incident heat flux, with the understandingthat the burning of the test specimen can
23、generate additionalheat flux to the specimen surface. The heat flux can also bemeasured at any time during a fire test, for example asdescribed in Guide E603, on any surface, and with measure-ment devices responding to radiative and convective fluxes.Typical units are kW/m2, kJ/(s m2), W/cm2, or BTU
24、/(s ft2).3.2.4 heat release rate, nthe heat evolved from thespecimen, per unit of time.3.2.5 ignitability, nthe propensity to ignition, as measuredby the time to sustained flaming, in seconds, at a specifiedheating flux.3.2.6 initial test heat flux, nthe heat flux set on the testapparatus at the ini
25、tiation of the test (see also heat flux).3.2.6.1 DiscussionThe initial test heat flux is the heat fluxvalue commonly used when describing or setting test condi-tions.3.2.7 net heat of combustion, nthe oxygen bomb (see TestMethod D5865) value for the heat of combustion, corrected forgaseous state of
26、product water.3.2.7.1 DiscussionThe net heat of combustion differsfrom the gross heat of combustion, in that the former assessesthe heat per unit mass generated from a combustion processFIG. 1 Modified Cone CalorimeterE2965 16a2that ends with water in the gaseous state, while the latter endswith wat
27、er in the liquid state.3.2.8 orientation, nthe plane in which the exposed face ofthe specimen is located during testing, either vertical orhorizontal facing up.3.2.9 oxygen consumption principle, nthe expression ofthe relationship between the mass of oxygen consumed duringcombustion and the heat rel
28、eased.3.2.10 smoke obscuration, nreduction of light transmis-sion by smoke, as measured by light attenuation.3.2.11 sustained flaming, nexistence of flame on or overmost of the specimen surface for periods of at least 4 s.3.2.11.1 DiscussionFlaming of less than 4 s duration isidentified as flashing
29、or transitory flaming.3.3 Symbols:As= nominal test specimen exposed surface area,0.0225m2.C = calibration constant for oxygen consumptionanalysis, m1/2kg1/2K1/2.hc= net heat of combustion, kJ/kg.hc,eff= effective heat of combustion, kJ/kg.I = actual beam intensity.Io= beam intensity with no smoke.k
30、= smoke extinction coefficient, m-1.L = extinction beam path length, m.m = test specimen mass, kg.mf= final test specimen mass, kg.mi= initial test specimen mass, kg.m = test specimen mass loss rate, kg/s.P = orifice meter pressure differential, Pa.Qtot= total heat released, kJ/m2(Note that kJ kWs).
31、q = heat release rate, kW.q = heat release rate per unit area, kW/m2.qmax= maximum heat release rate per unit area (kW/m2).q180= average heat release rate, per unit area, over thetime period starting at tigand ending 180 s later(kW/m2).r = repeatability (the units are the same as for thevariable bei
32、ng characterized).R = reproducibility (the units are the same as for thevariable being characterized).rO= stoichiometric oxygen/fuel mass ratio ().sr= sample-based standard deviation estimate for re-peatability (same units as r).sR= sample-based standard deviation estimate for repro-ducibility (same
33、 units as R).t = time, s.td= oxygen analyzer delay time, s.tig= time to sustained flaming (s). = density (kg/m3).t = sampling time interval, s.Te= absolute temperature of gas at the orifice meter, K.V = volume exhaust flow rate, measured at the locationof the laser photometer, m3/s.XO2= oxygen analy
34、zer reading, mole fraction O2().XO20= initial value of oxygen analyzer reading ().XO21= oxygen analyzer reading, before delay time correc-tion ().f= specific extinction area, for smoke, m2/kg.r= repeatability standard deviation (same units as r).R= reproducibility standard deviation (same units asR)
35、.4. Summary of Test Method4.1 This test method is based on the observation that,generally, the net heat of combustion is directly related to theamount of oxygen required for combustion. The relationship,known as the oxygen consumption principle, is that approxi-mately 13.1 103kJ of heat are released
36、 per 1 kg of oxygenconsumed. Test specimens in the test are burned in ambient airconditions, while being subjected to a predetermined initial testheat flux. In the test, the test specimens are exposed to apre-determined initial test heat flux, either with or without theadded use of a spark igniter.
37、The primary measurements areoxygen concentrations and exhaust gas flow rate, which areused to determine heat release rate and total heat released.Additional measurements include the mass-loss rate of the testspecimen, the time to sustained flaming and (optionally) smokeobscuration, or as required in
38、 the relevant material or perfor-mance standard.5. Significance and Use5.1 This test method is used primarily to determine the heatevolved in, or contributed to, a fire involving materials orproducts that emit low levels of heat release. The recom-mended use for this test method is for materials wit
39、h a totalheat release rate measured of less than 10 MJ over the first20 min test period, and which do not give peak heat releaserates of more than 200 kWm2for periods extending more than10 s. Also included is a determination of the effective heat ofcombustion, mass loss rate, the time to sustained f
40、laming, and(optionally) smoke production. These properties are deter-mined on small size test specimens that are representative ofthose in the intended end use.5.2 This test method is applicable to various categories ofproducts and is not limited to representing a single firescenario.5.3 This test m
41、ethod is not applicable to end-use productsthat do not have planar, or nearly planar, external surfaces.6. Apparatus6.1 General:6.1.1 The test apparatus shall be as described in TestMethod E1354 with the changes described below. Fig. 1 showsan overview of the apparatus.6.1.2 All dimensions given in
42、the figures that are followedby an asterisk are mandatory, and shall be followed withinnominal tolerances of 61 mm, unless otherwise specified.6.1.3 Additional details describing features and operation ofthe test apparatus are given in Ref (2).6.2 Conical Heater:6.2.1 The heater shall be similar to
43、that used in Test MethodE1354, but it shall be of a larger format and constructed suchthat it is capable of producing irradiance on the surface of thetest specimen of up to 80 kW/m2. The irradiance shall beE2965 16a3uniform within the central 100 mm by 100 mm area of theexposed test specimen surface
44、, to within 62 % and within63 % over the entire surface of the specimen. The heater shallconsist of electrical heater rods, tightly wound into the shape ofa truncated cone. The heater shall be encased on the outsidewith a double-wall stainless steel cone, packed with a refrac-tory fiber material of
45、approximately 100 kg/m3density.6.3 Test Specimen Mounting:6.3.1 The specimen holder is shown in Fig. 2. The bottomshall be constructed of 2.4 mm nominal stainless steel, and itshall have outside dimensions of 156 mm by 156 mm by a25 mm height (tolerance in dimensions: 62 mm).6.3.1.1 An open stainles
46、s steel square, 59 mm in insidedimensions, shall be spot welded to the underside of thespecimen holder, to facilitate the centering of the test specimenunder the cone heater. The leading edge of the open squareunderneath the specimen holder, which is the one opposite thehandle, is optional. The open
47、 square on the bottom of thespecimen holder shall be designed to seat with the samplemount assembly located at the top of the load cell, ensuringthat the specimen holder is centered with respect to the coneheater.6.3.2 The bottom of the specimen holder shall be lined witha layer of low density (nomi
48、nal density 65 kg/m3) refractoryfiber blanket with a thickness of at least 13 mm. The distancebetween the bottom surface of the cone heater and the top ofthe test specimen shall be adjusted to be 25 mm.6.3.2.1 If a test has been conducted and there was physicalcontact of the test specimen with the s
49、park igniter or the conebaseplate, that test shall be deemed invalid.6.3.3 Intumescent MaterialsThe testing technique to beused when testing intumescing test specimens shall be docu-mented in the test report. Options include those described in6.3.3.1 6.3.3.3.6.3.3.1 Use a retainer frame or edge frame (Fig. 3).NOTE 2The edge frame is used to reduce unrepresentative edgeFIG. 2 Specimen HolderNOTE 1All dimensions are in milimetres.NOTE 2* Indicates a critical dimension.E2965 16a4burning of test specimens.6.3.3.2 Use a wire gr
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