ASTM E1477-98a

Standard Test Method for Luminous Reflectance Factor of Acoustical Materials by Use of Integrating-Sphere Reflectometers

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 problems, 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

• Status: Historical
• Publication Date: 09-Dec-1998
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.02 - Spectrophotometry and Colorimetry

Relations

• Replaced By: ASTM E1477-98a(2003) - Standard Test Method for Luminous Reflectance Factor of Acoustical Materials by Use of Integrating-Sphere Reflectometers
• Effective Date: 10-Jul-2003

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E 1477 – 98a
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Luminous Reflectance Factor of Acoustical Materials by Use
1
of Integrating-Sphere Reflectometers
This standard is issued under the fixed designation E 1477; 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.
1. Scope (E 284)
3.1.2 luminous, adj—weighted according to the spectral
1.1 This test method covers the measurement of the lumi-
luminous efficiency function V (l) of the CIE. (E 284)
nous reflectance factor of acoustical materials for use in
3.1.3 reflectance factor, R, n—ratio of the flux reflected
predicting the levels of room illumination.
from the specimen to the flux reflected from the perfect
1.2 This standard does not purport to address all of the
reflecting diffuser under the same geometric and spectral
safety concerns, if any, associated with its use. It is the
conditions of measurement. (E 284)
responsibility of the user of this standard to establish appro-
3.1.4 perfect reflecting diffuser—ideal reflecting surface that
priate safety and health practices and determine the applica-
neither absorbs nor transmits light, but reflects light in a
bility of regulatory limitations prior to use.
diffused manner with the radiance of the reflecting surface
2. Referenced Documents
being the same for all reflecting angles, regardless of the
angular distribution of the incident light. (E 284)
2.1 ASTM Standards:
2
E 284 Terminology of Appearance
4. Summary of Test Method
E 308 Practice for Computing the Colors of Objects by
2 4.1 Test specimens are measured for (total) luminous reflec-
Using the CIE System
tance factor by standard color-measurement techniques using a
E 1164 Practice for Obtaining Spectrophotometric Data for
2 spectrophotometer, tristimulus (filter) colorimeter, or other
Object-Color Evaluation
3
reflectometer having a hemispherical optical measuring sys-
E 1264 Classification for Acoustical Ceiling Products
tem, such as an integrating sphere. The specular component is
E 1331 Test Method for Reflectance Factor and Color by
2
included to provide the total reflectance factor condition. The
Spectrophotometry Using Hemispherical Geometry
instrument standard is referenced to the perfect reflecting
E 1345 Practice for Reducing the Effect of Variability of
2
diffuser. Luminous reflectance factor is calculated as CIE
Color Measurement by Use of Multiple Measurements
tristimulus value Y for the CIE 1964 (10°) standard observer
E 1347 Test Method for Color and Color-Difference Mea-
2
and CIE standard illuminant D 65 (daylight) or F 2 (cool white
surement by Tristimulus (Filter) Colorimetry
fluorescent).
3. Terminology
5. Significance and Use
3.1 Definitions—Definitions of appearance terms in Termi-
5.1 Acoustical materials are often used as the entire ceiling
nology E 284 are applicable to this test method.
of rooms and are therefore an important component of the
3.1.1 integrating sphere, n—an optical device used either to
lighting system. The luminous reflectance of all important
collect flux reflected or transmitted from a specimen into a
components must be known in order to predict the level of
hemisphere or to provide isotropic irradiation of a specimen
illumination that will be obtained.
from a complete hemisphere, consisting of an approximately
5.2 The reflecting properties of a surface are measured
spherical cavity with apertures (ports) for admitting and
relative to those of a standard reflector, the perfect reflecting
detecting flux, and usually having additional apertures over
diffuser, to provide a reflectance factor. The luminous reflec-
which sample and reference specimens are placed and for
tance factor is calculated for a standard illuminant, and a
including or excluding the specularly reflected components.
standard observer, for the standard hemispherical (integrating-
sphere) geometry of illumination and viewing, in which all
1
reflected radiation from an area of the surface is collected. In
This test method is under the jurisdiction of ASTM Committee E-12 on Color
and Appearance and is the direct responsibility of Subcommittee E12.02 on
this way the reflecting properties of an acoustical material can
Spectrophotometry and Colorimetry.
be represented by a single number measured and calculated
Current edition approved December 10, 1998. Published February 1999. Origi-
under standard conditions.
nally published as E 1477-92. Last previous edition E 1477-98.
2
5.3 Acoustical materials generally have a non-gloss
...