ASTM E1477-98a(2013)
(Test Method)Standard Test Method for Luminous Reflectance Factor of Acoustical Materials by Use of Integrating-Sphere Reflectometers
Standard Test Method for Luminous Reflectance Factor of Acoustical Materials by Use of Integrating-Sphere Reflectometers
SIGNIFICANCE AND USE
5.1 Acoustical materials are often used as the entire ceiling of rooms and are therefore an important component of the lighting system. The luminous reflectance of all important components must be known in order to predict the level of illumination that will be obtained.
5.2 The reflecting properties of a surface are measured relative to those of a standard reflector, the perfect reflecting diffuser, to provide a reflectance factor. The luminous reflectance factor is calculated for a standard illuminant, and a standard observer, for the standard hemispherical (integrating-sphere) geometry of illumination and viewing, in which all reflected radiation from an area of the surface is collected. In this way the reflecting properties of an acoustical material can be represented by a single number measured and calculated under standard conditions.
5.3 Acoustical materials generally have a non-glossy white or near-white finish. The types of surface cover a wide range from smooth to deeply fissured. Measurement with integrating-sphere reflectometers has been satisfactory although multiple measurements may be required to sample the surface adequately. Instruments with other types of optical measuring systems may be used if it can be demonstrated that they provide equivalent results.
5.4 The use of this test method for determining the luminous reflectance factor is required by Classification E1264.
SCOPE
1.1 This test method covers the measurement of the luminous reflectance factor of acoustical materials for use in predicting the levels of room illumination.
1.2 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.
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Standards Content (Sample)
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Designation:E1477 −98a (Reapproved 2013)
Standard Test Method for
Luminous Reflectance Factor of Acoustical Materials by Use
of Integrating-Sphere Reflectometers
This standard is issued under the fixed designation E1477; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope from a complete hemisphere, consisting of an approximately
spherical cavity with apertures (ports) for admitting and
1.1 This test method covers the measurement of the lumi-
detecting flux, and usually having additional apertures over
nous reflectance factor of acoustical materials for use in
which sample and reference specimens are placed and for
predicting the levels of room illumination.
including or excluding the specularly reflected components.
1.2 This standard does not purport to address all of the
(E284)
safety concerns, if any, associated with its use. It is the
3.1.3 luminous, adj—weighted according to the spectral
responsibility of the user of this standard to establish appro-
luminous efficiency function V(λ) of the CIE. (E284)
priate safety and health practices and determine the applica-
3.1.4 reflectance factor, R, n—ratioofthefluxreflectedfrom
bility of regulatory limitations prior to use.
the specimen to the flux reflected from the perfect reflecting
2. Referenced Documents
diffuser under the same geometric and spectral conditions of
measurement. (E284)
2.1 ASTM Standards:
E284 Terminology of Appearance 3.1.5 perfect reflecting diffuser—ideal reflecting surface that
neither absorbs nor transmits light, but reflects light in a
E308 PracticeforComputingtheColorsofObjectsbyUsing
the CIE System diffused manner with the radiance of the reflecting surface
being the same for all reflecting angles, regardless of the
E1164 PracticeforObtainingSpectrometricDataforObject-
Color Evaluation angular distribution of the incident light. (E284)
E1264 Classification for Acoustical Ceiling Products
E1331 Test Method for Reflectance Factor and Color by 4. Summary of Test Method
Spectrophotometry Using Hemispherical Geometry
4.1 Test specimens are measured for (total) luminous reflec-
E1345 Practice for Reducing the Effect of Variability of
tance factor by standard color-measurement techniques using a
Color Measurement by Use of Multiple Measurements
spectrophotometer, tristimulus (filter) colorimeter, or other
E1347 Test Method for Color and Color-Difference Mea-
reflectometer having a hemispherical optical measuring
surement by Tristimulus Colorimetry
system, such as an integrating sphere. The specular component
isincludedtoprovidethetotalreflectancefactorcondition.The
3. Terminology
instrument standard is referenced to the perfect reflecting
3.1 Definitions:
diffuser. Luminous reflectance factor is calculated as CIE
3.1.1 Definitions of appearance terms in Terminology E284
tristimulus value Y for the CIE 1964 (10°) standard observer
are applicable to this test method.
and CIE standard illuminant D65 (daylight) or F2 (cool white
3.1.2 integrating sphere, n—an optical device used either to
fluorescent).
collect flux reflected or transmitted from a specimen into a
hemisphere or to provide isotropic irradiation of a specimen
5. Significance and Use
5.1 Acoustical materials are often used as the entire ceiling
of rooms and are therefore an important component of the
This test method is under the jurisdiction of ASTM Committee E12 on Color
lighting system. The luminous reflectance of all important
and Appearance and is the direct responsibility of Subcommittee E12.02 on
Spectrophotometry and Colorimetry.
components must be known in order to predict the level of
Current edition approved May 1, 2013. Published May 2013. Originally
illumination that will be obtained.
approved in 1992. Last previous edition approved in 2008 as E1477 – 98a (2008).
DOI: 10.1520/E1477-98AR13.
5.2 The reflecting properties of a surface are measured
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
relative to those of a standard reflector, the perfect reflecting
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
diffuser, to provide a reflectance factor. The luminous reflec-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. tance factor is calculated for a standard illuminant, and a
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E1477−98a (2013)
standard observer, for the standard hemispherical (integrating- 7.4 Additional test specimens or multiple measurements of
sphere) geometry of illumination and viewing, in which all each test specimen may be required to meet the tentative
reflected radiation from an area of the surface is collected. In tol
...
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