1、Designation: E662 12 E662 12a An 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 th
2、e 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This
3、fire-test-response standard covers determination of the specific optical density of smoke generated by solid materialsand assemblies mounted in the vertical position in thicknesses up to and including 1 in. (25.4 mm).1.2 Measurement is made of the attenuation of a light beam by smoke (suspended soli
4、d or liquid particles) accumulating withina closed chamber due to nonflaming pyrolytic decomposition and flaming combustion.1.3 Results are expressed in terms of specific optical density which is derived from a geometrical factor and the measuredoptical density, a measurement characteristic of the c
5、oncentration of smoke.1.4 This test method is intended for use in research and development and not as a basis for ratings for regulatory purposes.1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are
6、 provided for information only and are not considered standard.1.6 This standard measures and describes the response of materials, products, or assemblies to heat and flame under controlledconditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of
7、the materials, productsor assemblies under actual fire conditions.1.7 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 app
8、licability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2843 Test Method for Density of Smoke from the Burning or Decomposition of PlasticsE176 Terminology of Fire Standards3. Terminology3.1 DefinitionsFor definitions of terms found in this test method refer to T
9、erminology E176.4. 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) diameterarea of a ver
10、tically mounted specimen facing the radiant heater. The nominal 3 by 3-in. (76.2 by 76.2-mm) specimen is mountedwithin a holder which exposes an area measuring 2916 by 2916 in. (65.1 by 65.1 mm). The holder is able to accommodate specimensup to 1 in. (25.4 mm) thick. This exposure provides the nonfl
11、aming condition of the test.4.2 For the flaming condition, a six-tube burner is used to apply a row of equidistant flamelets across the lower edge of theexposed specimen area and into the specimen holder trough. This application of flame in addition to the specified irradiance levelfrom the heating
12、element constitutes the flaming combustion exposure.1 This test method is under the jurisdiction of ASTM Committee E05 on Fire Standards and is the direct responsibility of Subcommittee E05.21 on Smoke and CombustionProducts.Current edition approved July 1, 2012Nov. 1, 2012. Published August 2012Dec
13、ember 2012. Originally approved in 1979. Last previous edition approved in 20092012as E662 09.E662 12. DOI: 10.1520/E0662-12.10.1520/E0662-12A.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standards
14、volume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended 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 a
15、dequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
16、hocken, PA 19428-2959. United States14.3 The test specimens are exposed to the flaming and nonflaming conditions within a closed chamber. A photometric systemwith a vertical light path is used to measure the varying light transmission as smoke accumulates. The light transmittancemeasurements are use
17、d to calculate specific optical density of the smoke generated during the time period to reach the maximumvalue.35. Significance and Use5.1 This test method provides a means for determining the specific optical density of the smoke generated by specimens ofmaterials and assemblies under the specifie
18、d exposure conditions. Values determined by this test are specific to the specimen orassembly in the form and thickness tested and are not to be considered inherent fundamental properties of the material tested. Thus,it is likely that closely repeatable or reproducible experimental results are not t
19、o be expected from tests of a given material whenspecimen thickness, density, or other variables are involved.5.2 The photometric scale used to measure smoke by this test method is similar to the optical density scale for human vision.However, physiological aspects associated with vision are not mea
20、sured by this test method. Correlation with measurements byother test methods has not been established.45.3 At the present time no basis is provided for predicting the density of smoke generated by the materials upon exposure toheat and flame under other fire conditions.5.4 The test method is of a c
21、omplex nature and the data obtained are sensitive to variations which in other test methods mightbe considered to be insignificant (see Section 6). A precision statement based on the results of a roundrobin test by a prior draftversion of this test method is given in 14.15.5 In this procedure, the s
22、pecimens are subjected to one or more specific sets of laboratory test conditions. If different testconditions are substituted or the end-use conditions are changed, it is not always possible by or from this test method to predictchanges in the fire-test-response characteristics measured. Therefore,
23、 the results are valid only for the fire test exposure conditionsdescribed in this procedure.6. Limitations6.1 If during the test of one or more of the three replicate samples there occurs such unusual behavior as (1) the specimen fallingout of the holder, (2) melted material overflowing the sample
24、holder trough, (3) self-ignition in the pyrolysis mode, (4)extinguishment of the flame tiplets (even for a short period of time), or (5) a specimen being displaced from the zone of controlledirradiance, then an additional three samples of the identical preconditioned materials shall be tested in the
25、 test mode in which theunusual behavior occurred. Data obtained from the improper tests noted above shall not be incorporated in the averaged data butthe occurrence shall be reported. The test method is not suitable if more than three of the six replicates tested show thesecharacteristics.6.2 The te
26、st method has proven sensitive to small variations in sample geometry, surface orientation, thickness (either overallor individual layer), weight, and composition. It is, therefore, critical that the replicate samples be cut, sawed, or blanked toidentical sample areas, 3 by 3, +0, 0.03 in. (76.2 by
27、76.2, +0, 0.8 mm), and that records be kept of the respective weights withthe individual test data. It is feasible that evaluation of the obtained data together with the individual weights will assist in assessingthe reasons for any observed variability in measurements. Preselection of samples with
28、identical thickness or weight, or both, arepotential methods to reduce the variability but are likely to not be truly indicative of the actual variability to be expected from thematerial as normally supplied.6.3 The results of the test apply only to the thickness of the specimen as tested. There is
29、no common mathematical formula tocalculate the specific optical density of one thickness of a material when the specific optical density of another thickness of thesame material is known.6.4 The test method is sensitive to small variations of the position of the specimen and radiometer relative to t
30、he radiant heatsource.6.5 It is critical to clean the test chamber, and to remove accumulated residues from the walls when changing from one testmaterial to another, to ensure that chemical or physical recombination with the effluents or residues produced does not affect thedata obtained. Even when
31、testing the same material, excessive accumulations of residue shall not be permitted to build up sinceruggedness tests have indicated that such accumulations serve as additional insulators tending to reduce normally expectedcondensation of the aerosol, thereby raising the measured specific optical d
32、ensity.3 Additional parameters, such as the maximum rate of smoke accumulation, time to a fixed optical density level, or a smoke obscuration index provide potentially usefulinformation. See Appendix X1.4 Other test methods for measuring smoke available at the time of the publications referenced hav
33、e been reviewed and summarized in “The Control of Smoke in BuildingFiresA State of the Art Review.” Materials Research and Standards, Vol 42, April 1971, pp. 1623 and “A Report on Smoke Test Methods,” ASTM Standardization News,August 1976, pp. 1826.E662 12a26.6 With resilient samples, take extreme c
34、are to ensure that each replicate sample in its aluminum foil wrapper is installed sothat each protrudes identically through the front sample holder opening. Unequal protrusion will subject the samples to differenteffective irradiances and to slightly different ignition exposures. Excessive protrusi
35、on of specimens has the potential to cause dripsor 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 sensitive to small differences in conditioning (see Section 9). Many materialssuch as carpeting and thi
36、ck sections of wood, plastics, or plywood require long periods to attain equilibrium (constant weight) evenin a forced-draft humidification chamber.7. Apparatus7.1 Fig. 1 shows examples of the test apparatus, with a detailed description contained in the remainder of Section 7 and in AnnexA2. The app
37、aratus shall include the following:7.1.1 Test ChamberAs shown in Fig. 1, the test chamber shall be fabricated from laminated panels5 to provide insidedimensions of 36 by 24 by 36 6 18 in. (914 by 610 by 914 6 3 mm) for width, depth, and height, respectively. The interior surfacesshall consist of por
38、celain enameled metal, or equivalent coated metal other coated metal, which shall be resistant to chemical attackand corrosion, and suitable for periodic cleaning. Sealed windows shall be provided to accommodate a vertical photometric system.All other chamber penetrations shall be sealed. When all o
39、penings are closed, the chamber shall be capable of developing andmaintaining positive pressure during test periods, in accordance with 11.11.7.1.1.1 Fit the chamber with a safety blow-out panel, consisting of a sheet of aluminum foil of thickness not greater than 1.63 103 in. (0.04 mm) and having a
40、 minimum area of 125 in.2 (80 600 mm2), fastened in such a way as to provide an airtight seal.7.1.2 Radiant Heat FurnaceAs shown in Fig. 2, an electric furnace with a 3-in. (76.2-mm) diameter opening shall be usedto provide a constant irradiance on the specimen surface. The furnace shall be located
41、along the centerline equidistant between thefront and back of the chamber, with the opening facing toward and about 12 in. (305 mm) from the right wall. The centerline ofthe furnace shall be about 734 in. (195 mm) above the chamber floor. The furnace control system shall maintain the requiredirradia
42、nce level, under steady-state conditions with the chamber door closed, of 2.20 6 0.04 Btu/ft2s (2.50 6 0.05 W/cm2) for20 min. The control system shall consist of an autotransformer or alternative control device, and a voltmeter or other means formonitoring the electrical input. Where line voltage fl
43、uctuations exceed 62.5 , a constant voltage transformer is required to maintainthe prescribed irradiance level.7.1.3 Specimen HolderSpecimen holders shall conform in shape and dimension to that shown in Fig. 3 and be fabricated toexpose a 2916 by 2916-in. (65.1 by 65.1-mm) specimen area. Also shown
44、in Fig. 3 are the spring and rods for retaining the specimenwithin the holders.7.1.4 Framework for Support of Furnace and Specimen HolderThe furnace and specimen supporting framework shall beconstructed essentially in accordance with Fig. 4.7.1.5 Photometric SystemThe photometric system shall consis
45、t of a light source and photodetector, oriented vertically toreduce measurement variations resulting from stratification of the smoke generated by materials under test. The system shall beas shown in Figs. 5 and 6 and include the following:7.1.5.1 The light source shall be an incandescent lamp opera
46、ted at a fixed voltage in a circuit powered by a constant-voltagetransformer. The light source shall be mounted in a sealed and light-tight box. This box shall contain the necessary optics to providea collimated light beam passing vertically through the chamber. The light source shall be maintained
47、at an operating voltagerequired to provide a brightness temperature of 2200 6 100K.5 Commercially available panels of porcelain-enameled steel (interior surface) permanently laminated to an asbestos-magnesia core and backed with galvanized steel(exterior surface), total thickness 316 in. (9.6 mm), h
48、ave been found suitable.E662 12a37.1.5.2 The photodetector shall be a photomultiplier tube, with an S-4 spectral sensitivity response and a dark current less than109 A. A set of nine gelatin compensating filters varying from 0.1 to 0.9 neutral density are mounted one or more as required inthe optica
49、l measuring system to correct for differences in the luminous sensitivity of the photomultiplier tube. These filters alsoprovide correction for light source or photomultiplier aging and reduction in light transmission, through discolored or abradedoptical windows. An additional criterion for selection of photomultiplier tubes requires a minimum sensitivity equivalent to thatrequired to give a full scale reading with only the No. 5 compensating filter in the light path. A light-tight box located directlyAPhotomultiplier tube housing NFlowmeter shutoff
