ASTM E662-97
(Test Method)Standard Test Method for Specific Optical Density of Smoke Generated by Solid Materials
Standard Test Method for Specific Optical Density of Smoke Generated by Solid Materials
SCOPE
1.1 This fire-test-response standard covers determination of the specific optical density of smoke generated by solid materials and 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 solid or liquid particles) accumulating within a 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 measured optical density, a measurement characteristic of the concentration 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 This standard should be used to measure and describe the response of materials, products, or assemblies to heat and flame under controlled conditions and should not be used to describe or appraise the fire-hazard or fire-risk of materials, products, of assemblies under actual fire conditions. However, results of the test may be used as elements of a fire-hazard assessment or a fire-risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard or fire risk of a particular end use.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
1.7 The values stated in inch-pound units are to be regarded as standard. Values stated in parentheses are for information only.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 662 – 97 An American National Standard
Standard Test Method for
Specific Optical Density of Smoke Generated by Solid
Materials
This standard is issued under the fixed designation E 662; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) 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. Scope ing or Decomposition of Plastics
E 176 Terminology of Fire Standards
1.1 This fire-test-response standard covers determination of
the specific optical density of smoke generated by solid
3. Terminology
materials and assemblies mounted in the vertical position in
3.1 Definitions—For definitions of terms found in this test
thicknesses up to and including 1 in. (25.4 mm).
method refer to Terminology E 176.
1.2 Measurement is made of the attenuation of a light beam
by smoke (suspended solid or liquid particles) accumulating
4. Summary of Test Method
within a closed chamber due to nonflaming pyrolytic decom-
4.1 This test method employs an electrically heated radiant-
position and flaming combustion.
energy source mounted within an insulated ceramic tube and
1.3 Results are expressed in terms of specific optical density
positioned so as to produce an irradiance level of 2.2 Btu/
which is derived from a geometrical factor and the measured
2 2
s·ft (2.5 W/cm ) averaged over the central 1.5-in. (38.1-mm)
optical density, a measurement characteristic of the concentra-
diameter area of a vertically mounted specimen facing the
tion of smoke.
radiant heater. The nominal 3 by 3-in. (76.2 by 76.2-mm)
1.4 This test method is intended for use in research and
specimen is mounted within a holder which exposes an area
development and not as a basis for ratings for regulatory
9 9
measuring 2 ⁄16 by 2 ⁄16 in. (65.1 by 65.1 mm). The holder can
purposes.
accommodate specimens up to 1 in. (25.4 mm) thick. This
1.5 This standard should be used to measure and describe
exposure provides the nonflaming condition of the test.
the response of materials, products, or assemblies to heat and
4.2 For the flaming condition, a six-tube burner is used to
flame under controlled conditions and should not be used to
apply a row of equidistant flamelets across the lower edge of
describe or appraise the fire-hazard or fire-risk of materials,
the exposed specimen area and into the specimen holder
products, of assemblies under actual fire conditions. However,
trough. This application of flame in addition to the specified
results of the test may be used as elements of a firehazard
irradiance level from the heating element constitutes the
assessment or a fire-risk assessment which takes into account
flaming combustion exposure.
all of the factors which are pertinent to an assessment of the
4.3 The test specimens are exposed to the flaming and
fire hazard or fire risk of a particular end use.
nonflaming conditions within a closed chamber. A photometric
1.6 This standard does not purport to address all of the
system with a vertical light path is used to measure the varying
safety concerns, if any, associated with its use. It is the
light transmission as smoke accumulates. The light transmit-
responsibility of the user of this standard to establish appro-
tance measurements are used to calculate specific optical
priate safety and health practices and determine the applica-
density of the smoke generated during the time period to reach
bility of regulatory limitations prior to use.
the maximum value.
1.7 The values stated in inch-pound units are to be regarded
as standard. Values stated in parentheses are for information
5. Significance and Use
only.
5.1 This test method provides a means for determining the
specific optical density of the smoke generated by specimens of
2. Referenced Documents
materials and assemblies under the specified exposure condi-
2.1 ASTM Standards:
tions. Values determined by this test are specific to the
D 2843 Test Method for Density of Smoke from the Burn-
1 2
This test method is under the jurisdiction of ASTM Committee E-5 on Fire Annual Book of ASTM Standards, Vol 08.02.
Standards and is the direct responsibility of Subcommittee E05.21 on Smoke and Annual Book of ASTM Standards, Vol 04.07.
Combustion Products. Additional parameters, such as the maximum rate of smoke accumulation, time
Current edition approved Sept. 10, 1997. Published April 1998. Originally to a fixed optical density level, or a smoke obscuration index may provide useful
published as E 662 – 79. Last previous edition E 662 – 95. information. See Appendix X1.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 662
specimen or assembly in the form and thickness tested and are 6.3 The results of the test apply only to the thickness of the
not to be considered inherent fundamental properties of the specimen as tested. There is not a common mathematical
material tested. Thus, closely repeatable or reproducible ex- formula that can be used to calculate the specific optical
perimental results should not be expected from tests of a given density of one thickness of a material when the specific optical
material when specimen thickness, density, or other variables density of another thickness of the same material is known.
are involved. 6.4 The test method is sensitive to small variations of the
5.2 The photometric scale used to measure smoke by this position of the specimen and radiometer relative to the radiant
test method is similar to the optical density scale for human heat source.
vision. However, physiological aspects associated with vision 6.5 Sensitivity to variations in composition requires that,
are not measured by this test method. Correlation with mea- when changing to another material to be tested, it may first be
surements by other test methods has not been established. necessary to clean and remove from the walls the accumulated
5.3 At the present time no basis is provided for predicting residues to assure that chemical or physical recombination with
the density of smoke that may be generated by the materials the effluents or residues produced by the pyrolysis does not
upon exposure to heat and flame under other fire conditions. affect the data obtained. Even when testing the same material,
5.4 The test method is of a complex nature and the data excessive accumulations of residue should not be permitted to
obtained are sensitive to variations which in other test methods build up since ruggedness tests have indicated that such serve
might be considered to be insignificant (see Section 6). A as additional insulators tending to reduce normally expected
precision statement based on the results of a roundrobin test by condensation of the aerosol, thereby raising the measured
a prior draft version of this test method is given in 14.1 specific optical density.
5.5 In this procedure, the specimens are subjected to one or 6.6 With resilient samples extreme care must be taken to
more specific sets of laboratory test conditions. If different test assure that each replicate sample in its aluminum foil wrapper
conditions are substituted or the end-use conditions are is installed so that each protrudes identically through the front
changed, it may not be possible by or from this test to predict sample holder opening. Unequal protrusion will subject the
changes in the fire-test-response characteristics measured. samples to different effective irradiances and to slightly differ-
Therefore, the results are valid only for the fire-test-exposure ent ignition exposures. Specimens that protrude excessively
conditions described in this procedure. may drip or sag onto the burner, clogging the flame jets and
thereby invalidate the test.
6. Limitations
6.7 The measurements obtained have also proven sensitive
6.1 If during the test of one or more of the three replicate
to small differences in conditioning (see Section 9). Many
samples there occurs such unusual behavior as (1) the speci-
materials such as carpeting and thick sections of wood,
men falling out of the holder, (2) melted material overflowing
plastics, or plywood require long periods to attain equilibrium
the sample holder trough, (3) self-ignition in the pyrolysis
(constant weight) even in a forced-draft humidification cham-
mode, (4) extinguishment of the flame tiplets (even for a short
ber.
period of time), or (5) a specimen being displaced from the
7. Apparatus
zone of controlled irradiance, then an additional three samples
of the identical preconditioned materials should be tested in the
7.1 The apparatus shall be essentially as shown in Figs. 1
test mode in which the unusual behavior occurred. Data
and 2. A more detailed description of suggested details is given
obtained from the improper tests noted above shall not be
in Annex A2. The apparatus shall include the following:
incorporated in the averaged data but the occurrence should be
7.1.1 Test Chamber—As shown in Fig. 2, the test chamber
reported. The test method is not suitable if more than three of
shall be fabricated from laminated panels to provide inside
the six replicates tested show these characteristics. 1
dimensions of 36 by 24 by 36 6 ⁄8 in. (914 by 610 by 914 6
6.2 The test method has proven sensitive to small variations
3 mm) for width, depth, and height, respectively. The interior
in sample geometry, surface orientation, thickness (either
surfaces shall consist of porcelainenameled metal, or equiva-
overall or individual layer), weight, and composition. It is,
lent coated metal resistant to chemical attack and corrosion,
therefore, critical that the replicate samples be cut, sawed, or
and suitable for periodic cleaning. Sealed windows shall be
blanked to identical sample areas, 3 by 3, +0, −0.03 in. (76.2
provided to accommodatea vertical photometric system. All
by 76.2, +0, −0.8 mm), and that records be kept of the
other chamber penetrations shall be sealed. When all openings
respective weights with the individual test data. Evaluation of
are closed, the chamber shall be capable of developing and
the obtained data together with the individual weights may
maintaining positive pressure during test periods, in accor-
assist in assessing the reasons for any observed variability in
dance with 11.11.
measurements. Preselection of samples with identical thickness
7.1.2 Radiant Heat Furnace—As shown in Fig. 3, an
or weight, or both, may reduce the variability but may not be
electric furnace with a 3-in. (76.2-mm) diameter opening shall
truly indicative of the actual variability to be expected from the
be used to provide a constant irradiance on the specimen
material as normally supplied.
surface. The furnace shall be located along the centerline
Other test methods for measuring smoke have been reviewed and summarized
in “The Control of Smoke in Building Fires—A State of the Art Review.” Materials Commercially available panels of porcelain-enameled steel (interior surface)
Research and Standards, Vol 42, April 1971, pp. 16–23 and “A Report on Smoke permanently laminated to an asbestos-magnesia core and backed with galvanized
Test Methods,” ASTM Standardization News, August 1976, pp. 18–26. steel (exterior surface), total thickness ⁄16 in. (9.6 mm), have been found suitable.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 662
voltage transformer. The light source shall be mounted in a
sealed and light-tight box. This box shall contain the necessary
optics to provide a collimated light beam passing vertically
through the chamber. The light source shall be maintained at an
operating voltage required to provide a brightness temperature
of 2200 6 100°K.
7.1.5.2 The photodetector shall be a photomultiplier tube,
with an S-4 spectral sensitivity response and a dark current less
−9
than 10 A. A set of nine gelatin compensating filters varying
from 0.1 to 0.9 neutral density are mounted one or more as
required in the optical measuring system to correct for differ-
ences in the luminous sensitivity of the photomultiplier tube.
These filters also provide correction for light source or photo-
multiplier aging and reduction in light transmission, through
discolored or abraded optical windows. An additional criterion
for selection of photomultiplier tubes requires a minimum
sensitivity equivalent to that required to give a full scale
reading with only the No. 5 compensating filter in the light
path. A light-tight box located directly opposite the light source
shall be provided to mount the photodetector housing and the
associated optics. A glass window shall be used to isolate the
photodetector and its optics from the chamber atmosphere.
7.1.5.3 In addition to the above compensating filter, a
neutral density range extender filter permitting the system to
measure to Optical Density 6 is incorporated in the commercial
version of the smoke density chamber. The accuracy of
read-outs in the range above D 528 is affected by the excessive
s
light scattering present in such heavy smoke concentration.
Where D values over 500 are measured, it is necessary to
s
provide a chamber window cover to prevent room light from
being scattered into the photomultiplier, thereby providing an
FIG. 1 Smoke Density Chamber
incorrect higher transmission value.
equidistant between the front and back of the chamber, with the
7.1.6 Radiometer—The radiometer for standardizing the
opening facing toward and about 12 in. (305 mm) from the
output of the radiant heat furnace shall be of the circular foil
right wall. The centerline of the furnace shall be about 7 ⁄4 in.
type, the operation of which was described by Gardon. The
(195 mm) above the chamber floor. The furnace control system
construction of the radiometer shall be as shown in Fig. 8. It
shall maintain the required irradiance level, under steady-state
shall have a stainless steel reflective heat shield with a 1 ⁄2-in.
conditions with the chamber door closed, of 2.20 6 0.04
(38.1-mm) aperature on the front and a finned cooler supplied
2 2
Btu/ft ·s (2.50 6 0.05 W/cm ) for 20 min. The control system
with compressed air mounted on the rear to maintain a constant
shall consist of an autotransformer or alternative control
body temperature of 200 6 5°F (93 6 3°C).
device, and a voltmeter
...
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