ASTM E307-72(2002)
(Test Method)Standard Test Method for Normal Spectral Emittance at Elevated Temperatures
Standard Test Method for Normal Spectral Emittance at Elevated Temperatures
SCOPE
1.1 This test method describes a highly accurate technique for measuring the normal spectral emittance of electrically conducting materials or materials with electrically conducting substrates, in the temperature range from 600 to 1400 K, and at wavelengths from 1 to 35 μm.
1.2 The test method requires expensive equipment and rather elaborate precautions, but produces data that are accurate to within a few percent. It is suitable for research laboratories where the highest precision and accuracy are desired, but is not recommended for routine production or acceptance testing. However, because of its high accuracy this test method can be used as a referee method to be applied to production and acceptance testing in cases of dispute.
1.3 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.4 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.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E307–72 (Reapproved 2002)
Standard Test Method for
1
Normal Spectral Emittance at Elevated Temperatures
This standard is issued under the fixed designation E307; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope conditions. Emittance must be further qualified in order to
convey a more precise meaning. Thermal-radiant exitance that
1.1 This test method describes a highly accurate technique
occurs in all possible directions is referred to as hemispherical
for measuring the normal spectral emittance of electrically
thermal-radiant exitance. When limited directions of propaga-
conducting materials or materials with electrically conducting
tion or observation are involved, the word directional thermal-
substrates,inthetemperaturerangefrom600to1400K,andat
radiantexitanceisused.Thus,normalthermal-radiantexitance
wavelengths from 1 to 35 µm.
is a special case of directional thermal-radiant exitance, and
1.2 The test method requires expensive equipment and
means in a direction perpendicular (normal) to the surface.
rather elaborate precautions, but produces data that are accu-
Therefore, spectral normal emittance refers to the radiant flux
rate to within a few percent. It is suitable for research
emitted by a specimen within a narrow wavelength interval
laboratories where the highest precision and accuracy are
centered on a specific wavelength and emitted in a direction
desired, but is not recommended for routine production or
normal to the plane of an incremental area of a specimen’s
acceptance testing. However, because of its high accuracy this
surface. These restrictions in angle occur usually by the
test method can be used as a referee method to be applied to
method of measurement rather than by radiant flux emission
production and acceptance testing in cases of dispute.
properties.
1.3 The values stated in SI units are to be regarded as the
standard. The values in parentheses are for information only.
NOTE 1—All the terminology used in this test method has not been
1.4 This standard does not purport to address all of the standardized. Terminology E349 contain some approved terms. When
agreement on other standard terms is reached, the definitions used herein
safety concerns, if any, associated with its use. It is the
will be revised as required.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Summary of Test Method
bility of regulatory limitations prior to use.
4.1 The principle of the test method is a direct comparison
2. Referenced Documents of the radiant flux from a specimen at a given temperature to
the radiant flux of a blackbody at the same temperature and
2.1 ASTM Standards:
2
under the same environmental conditions of atmosphere and
E349 Terminology Relating to Space Simulation
pressure. The details of this test method are given by Harrison
3. Terminology
et al (3) and Richmond et al (4).
4.2 The essential features of the test method are the use of
3.1 Definitions of Terms Specific to This Standard:
adouble-beamratio-recordinginfraredspectrophotometerwith
3.1.1 spectral normal emittance—the term as used in this
3
variable slit widths, which combines and compares the signals
specification follows that advocated by Jones (1), Worthing
from the specimen and the reference blackbody through a
(2), and others, in that the word emittance is a property of a
monochromator system which covers the wavelength range
specimen; it is the ratio of radiant flux emitted by a specimen
from 1 to 35 µm (Note 2). According to Harrison et al (3) a
per unit area (thermal-radiant exitance) to that emitted by a
differential thermocouple with suitable instrumentation is used
blackbodyradiatoratthesametemperatureandunderthesame
to maintain a heated specimen and the blackbody at the same
temperature.
1
This test method is under the jurisdiction of ASTM Committee E21 on Space
4
NOTE 2—Anelectronic-null,ratio-recordingspectrophotometer ispre-
Simulation andApplications of SpaceTechnology and is the direct responsibility of
Subcommittee E21.04 on Space Simulation Test Methods. ferred to an optical-null instrument for this use. It may be difficult to
Current edition approved Sept. 29, 1972. Published November 1972. Originally
obtain and maintain linearity of response of an optical-null instrument if
published as E307 – 68 T. Last previous edition E307 – 68 T.
2
Annual Book of ASTM Standards, Vol 15.03.
3
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
4
this test method. The Perkin-Elmer Model 13U has been found satisfacto
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.