1、Designation: E662 12An American National StandardStandard Test Method forSpecific Optical Density of Smoke Generated by SolidMaterials1This standard is issued under the fixed designation E662; 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This fire-test-
3、response standard covers determination ofthe specific optical density of smoke generated by solidmaterials and assemblies mounted in the vertical position inthicknesses up to and including 1 in. (25.4 mm).1.2 Measurement is made of the attenuation of a light beamby smoke (suspended solid or liquid p
4、articles) accumulatingwithin a closed chamber due to nonflaming pyrolytic decom-position and flaming combustion.1.3 Results are expressed in terms of specific optical densitywhich is derived from a geometrical factor and the measuredoptical density, a measurement characteristic of the concentra-tion
5、 of smoke.1.4 This test method is intended for use in research anddevelopment and not as a basis for ratings for regulatorypurposes.1.5 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for i
6、nformation onlyand are not considered standard.1.6 This standard 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, prod
7、ucts or assemblies under actual fire conditions.1.7 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 and health practices and determine the applica-bility of reg
8、ulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2843 Test Method for Density of Smoke from the Burningor Decomposition of PlasticsE176 Terminology of Fire Standards3. Terminology3.1 DefinitionsFor definitions of terms found in this testmethod refer to Terminology E176.4.
9、 Summary of Test Method4.1 This test method employs an electrically heated radiant-energy source mounted within an insulated ceramic tube andpositioned so as to produce an irradiance level of 2.2 Btu/sft2(2.5 W/cm2) averaged over the central 1.5-in. (38.1-mm)diameter area of a vertically mounted spe
10、cimen facing theradiant heater. The nominal 3 by 3-in. (76.2 by 76.2-mm)specimen is mounted within a holder which exposes an areameasuring 2916 by 2916 in. (65.1 by 65.1 mm). The holder isable to accommodate specimens up to 1 in. (25.4 mm) thick.This exposure provides the nonflaming condition of the
11、 test.4.2 For the flaming condition, a six-tube burner is used toapply a row of equidistant flamelets across the lower edge ofthe exposed specimen area and into the specimen holdertrough. This application of flame in addition to the specifiedirradiance level from the heating element constitutes thef
12、laming combustion exposure.4.3 The test specimens are exposed to the flaming andnonflaming conditions within a closed chamber. A photometricsystem with a vertical light path is used to measure the varying1This test method is under the jurisdiction of ASTM Committee E05 on FireStandards and is the di
13、rect responsibility of Subcommittee E05.21 on Smoke andCombustion Products.Current edition approved July 1, 2012. Published August 2012. Originallyapproved in 1979. Last previous edition approved in 2009 as E662 09. DOI:10.1520/E0662-12.2For referenced ASTM standards, visit the ASTM website, www.ast
14、m.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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.light tra
15、nsmission as smoke accumulates. The light transmit-tance measurements are used to calculate specific opticaldensity of the smoke generated during the time period to reachthe maximum value.35. Significance and Use5.1 This test method provides a means for determining thespecific optical density of the
16、 smoke generated by specimens ofmaterials and assemblies under the specified exposure condi-tions. Values determined by this test are specific to thespecimen or assembly in the form and thickness tested and arenot to be considered inherent fundamental properties of thematerial tested. Thus, it is li
17、kely that closely repeatable orreproducible experimental results are not to be expected fromtests of a given material when specimen thickness, density, orother variables are involved.5.2 The photometric scale used to measure smoke by thistest method is similar to the optical density scale for humanv
18、ision. However, physiological aspects associated with visionare not measured by this test method. Correlation with mea-surements by other test methods has not been established.45.3 At the present time no basis is provided for predictingthe density of smoke generated by the materials upon exposureto
19、heat and flame under other fire conditions.5.4 The test method is of a complex nature and the dataobtained are sensitive to variations which in other test methodsmight be considered to be insignificant (see Section 6). Aprecision statement based on the results of a roundrobin test bya prior draft ve
20、rsion of this test method is given in 14.15.5 In this procedure, the specimens are subjected to one ormore specific sets of laboratory test conditions. If different testconditions are substituted or the end-use conditions arechanged, it is not always possible by or from this test methodto predict ch
21、anges in the fire-test-response characteristicsmeasured. Therefore, the results are valid only for the fire testexposure conditions described in this procedure.6. Limitations6.1 If during the test of one or more of the three replicatesamples there occurs such unusual behavior as (1) the speci-men fa
22、lling out of the holder, (2) melted material overflowingthe sample holder trough, (3) self-ignition in the pyrolysismode, (4) extinguishment of the flame tiplets (even for a shortperiod of time), or (5) a specimen being displaced from thezone of controlled irradiance, then an additional three sample
23、sof the identical preconditioned materials shall be tested in thetest mode in which the unusual behavior occurred. Dataobtained from the improper tests noted above shall not beincorporated in the averaged data but the occurrence shall bereported. The test method is not suitable if more than three of
24、the six replicates tested show these characteristics.6.2 The test method has proven sensitive to small variationsin sample geometry, surface orientation, thickness (eitheroverall or individual layer), weight, and composition. It is,therefore, critical that the replicate samples be cut, sawed, orblan
25、ked to identical sample areas, 3 by 3, +0, 0.03 in. (76.2by 76.2, +0, 0.8 mm), and that records be kept of therespective weights with the individual test data. It is feasiblethat evaluation of the obtained data together with the individualweights will assist in assessing the reasons for any observed
26、variability in measurements. Preselection of samples withidentical thickness or weight, or both, are potential methods toreduce the variability but are likely to not be truly indicative ofthe actual variability to be expected from the material asnormally supplied.6.3 The results of the test apply on
27、ly to the thickness of thespecimen as tested. There is no common mathematical formulato calculate the specific optical density of one thickness of amaterial when the specific optical density of another thicknessof the same material is known.6.4 The test method is sensitive to small variations of the
28、position of the specimen and radiometer relative to the radiantheat source.6.5 It is critical to clean the test chamber, and to removeaccumulated residues from the walls when changing from onetest material to another, to ensure that chemical or physicalrecombination with the effluents or residues pr
29、oduced does notaffect the data obtained. Even when testing the same material,excessive accumulations of residue shall not be permitted tobuild up since ruggedness tests have indicated that suchaccumulations serve as additional insulators tending to reducenormally expected condensation of the aerosol
30、, thereby raisingthe measured specific optical density.6.6 With resilient samples, take extreme care to ensure thateach replicate sample in its aluminum foil wrapper is installedso that each protrudes identically through the front sampleholder opening. Unequal protrusion will subject the samples tod
31、ifferent effective irradiances and to slightly different ignitionexposures. Excessive protrusion of specimens has the potentialto cause drips or for the specimen to sag onto the burner,clogging the flame jets and thereby invalidating the test.6.7 The measurements obtained have also proven sensitivet
32、o small differences in conditioning (see Section 9). Manymaterials such as carpeting and thick sections of wood,plastics, or plywood require long periods to attain equilibrium(constant weight) even in a forced-draft humidification cham-ber.7. Apparatus7.1 Fig. 1 shows examples of the test apparatus,
33、 with adetailed description contained in the remainder of Section 7and in Annex A2. The apparatus shall include the following:7.1.1 Test ChamberAs shown in Fig. 1, the test chambershall be fabricated from laminated panels5to provide insidedimensions of 36 by 24 by 36 618 in. (914 by 610 by 914 63Add
34、itional parameters, such as the maximum rate of smoke accumulation, timeto a fixed optical density level, or a smoke obscuration index provide potentiallyuseful information. See Appendix X1.4Other test methods for measuring smoke available at the time of the publica-tions referenced have been review
35、ed and summarized in “The Control of Smoke inBuilding FiresAState of theArt Review.” Materials Research and Standards,Vol42, April 1971, pp. 1623 and “A Report on Smoke Test Methods,” ASTMStandardization News, August 1976, pp. 1826.5Commercially available panels of porcelain-enameled steel (interior
36、 surface)permanently laminated to an asbestos-magnesia core and backed with galvanizedsteel (exterior surface), total thickness316 in. (9.6 mm), have been found suitable.E662 1223 mm) for width, depth, and height, respectively. The interiorsurfaces shall consist of porcelain enameled metal, or equiv
37、a-lent coated metal resistant to chemical attack and corrosion,and suitable for periodic cleaning. Sealed windows shall beprovided to accommodate a vertical photometric system. Allother chamber penetrations shall be sealed. When all openingsare closed, the chamber shall be capable of developing andm
38、aintaining positive pressure during test periods, in accor-dance with 11.11.APhotomultiplier tube housing NFlowmeter shutoff valvesBChamber OSample mover knobCBlow-out panel (in floor of chamber) PLight source switchDHinged door with window QLight source voltage jacksEExhaust vent control RLine swit
39、chFRadiometer output jacks SBase cabinetGTemperature (wall) indicator TIndicating lampsHAutotransformer UMicrophotometer (photomultiplier)IFurnace switch VOptical system rodsJVoltmeter (furnace) WOptical system floor windowKFuse holder (furnace) XExhaust vent damperLRadiometer air flowmeter YInlet v
40、ent damperMGas and air (burner) flowmeter ZAccess portsFIG. 1 Smoke Density Chamber AssemblyE662 1237.1.1.1 Fit the chamber with a safety blow-out panel,consisting of a sheet of aluminum foil of thickness not greaterthan 1.63 3 103in. (0.04 mm) and having a minimum area of125 in.2(80 600 mm2), faste
41、ned in such a way as to provide anairtight seal.7.1.2 Radiant Heat FurnaceAs shown in Fig. 2,anelectric furnace with a 3-in. (76.2-mm) diameter opening shallbe used to provide a constant irradiance on the specimensurface. The furnace shall be located along the centerlineequidistant between the front
42、 and back of the chamber, with theopening facing toward and about 12 in. (305 mm) from theright wall. The centerline of the furnace shall be about 734 in.(195 mm) above the chamber floor. The furnace control systemshall maintain the required irradiance level, under steady-stateconditions with the ch
43、amber door closed, of 2.20 6 0.04Btu/ft2s (2.50 6 0.05 W/cm2) for 20 min. The control systemshall consist of an autotransformer or alternative controldevice, and a voltmeter or other means for monitoring theelectrical input. Where line voltage fluctuations exceed 62.5 ,a constant voltage transformer
44、 is required to maintain theprescribed irradiance level.7.1.3 Specimen HolderSpecimen holders shall conform inshape and dimension to that shown in Fig. 3 and be fabricatedto expose a 2916 by 2916-in. (65.1 by 65.1-mm) specimen area.Also shown in Fig. 3 are the spring and rods for retaining thespecim
45、en within the holders.7.1.4 Framework for Support of Furnace and SpecimenHolderThe furnace and specimen supporting frameworkshall be constructed essentially in accordance with Fig. 4.7.1.5 Photometric SystemThe photometric system shallconsist of a light source and photodetector, oriented verticallyt
46、o reduce measurement variations resulting from stratificationof the smoke generated by materials under test. The systemshall be as shown in Figs. 5 and 6 and include the following:AStainless steel tube GStainless steel spacersBFront insulating ring HStainless steel reflectors (3)CCeramic tube JCente
47、r insulating diskDHeater/plate 525 W KInsulating spacer ringEStainless steel mounting screw LRear insulating diskFInsulating gasket MSheet metal screw (2)PHeater leads/porcelain beadsFIG. 2 Furnace SectionE662 124FIG. 3 Details of Specimen Holder and Pilot BurnerFIG. 4 Furnace SupportE662 1257.1.5.1
48、 The light source shall be an incandescent lampoperated at a fixed voltage in a circuit powered by a constant-voltage transformer. The light source shall be mounted in asealed and light-tight box. This box shall contain the necessaryoptics to provide a collimated light beam passing verticallythrough
49、 the chamber. The light source shall be maintained at anoperating voltage required to provide a brightness temperatureof 2200 6 100K.APhotomultiplier housing KOptical system platforms (2)BPhotomultiplier tube and socket LOptical windows (2)CUpper shutter blade, with ND2 filter over one aperture MChamber roofDLower shutter blade, with single aperture NAlignment rods (3)EOpal diffuser filter PParallel light beam, 1.5-in. (37.5-mm) diameterFAperature disk QChamber floorGNeutral density compensating filter (
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