ASTM E1477-98a(2022)

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2022
• ICS: 17.180.20 - Colours and measurement of light
• ICS: 91.120.20 - Acoustics in building. Sound insulation
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.02 - Spectrophotometry and Colorimetry

Relations

• Refers: ASTM E1331-15(2023) - Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry
• Effective Date: 01-Nov-2023
• Refers: ASTM E1164-23 - Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation
• Effective Date: 01-Nov-2023
• Refers: ASTM E1347-06(2020) - Standard Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
• Effective Date: 01-May-2020
• Refers: ASTM E1331-15(2019) - Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry
• Effective Date: 01-Nov-2019
• Refers: ASTM E1345-98(2019) - Standard Practice for Reducing the Effect of Variability of Color Measurement by Use of Multiple Measurements
• Effective Date: 01-May-2019
• Refers: ASTM E308-17 - Standard Practice for Computing the Colors of Objects by Using the CIE System
• Effective Date: 01-May-2017
• Refers: ASTM E1347-06(2015) - Standard Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
• Effective Date: 01-Nov-2015
• Refers: ASTM E1331-15 - Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry
• Effective Date: 01-Jul-2015
• Refers: ASTM E308-15 - Standard Practice for Computing the Colors of Objects by Using the CIE System
• Effective Date: 01-Apr-2015
• Refers: ASTM E1345-98(2014) - Standard Practice for Reducing the Effect of Variability of Color Measurement by Use of Multiple Measurements
• Effective Date: 01-Nov-2014
• Refers: ASTM E1264-14 - Standard Classification for Acoustical Ceiling Products
• Effective Date: 01-Oct-2014
• Refers: ASTM E284-13b - Standard Terminology of Appearance
• Effective Date: 01-Nov-2013
• Refers: ASTM E284-13a - Standard Terminology of Appearance
• Effective Date: 01-Jun-2013
• Refers: ASTM E284-13 - Standard Terminology of Appearance
• Effective Date: 01-Jan-2013
• Refers: ASTM E1164-12e1 - Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation
• Effective Date: 01-Jul-2012

Overview

ASTM E1477-98a(2022) is the internationally recognized standard test method for measuring the luminous reflectance factor of acoustical materials using integrating-sphere reflectometers. Developed by ASTM International, this standard plays a critical role in the prediction and optimization of room illumination by evaluating the reflecting properties of ceiling and wall components commonly used in building interiors. The method ensures consistent, reliable, and reproducible results for manufacturers, designers, and engineers concerned with acoustics and lighting in built environments.

Key Topics

• Luminous Reflectance Factor
  This parameter quantifies the amount of visible light reflected by acoustical materials relative to a perfect reflecting diffuser under standardized conditions. It is pivotal for predicting the visual brightness and efficiency of lighting systems.

• Integrating-Sphere Reflectometers
  The standard prescribes the use of integrating sphere devices, which collect all reflected light from a test surface within a hemisphere, providing accurate and comprehensive measurement for surfaces with varying textures and finishes.

• Specimen Measurement
  ASTM E1477 requires:

  • At least three randomly selected test specimens from each lot
  • Measurements using hemispherical geometry with the specular component included
  • Calibration of instruments against a perfect reflecting diffuser

• Surface Types
  The test method is applicable to acoustical materials often characterized by non-glossy, white or near-white finishes, ranging from smooth to deeply fissured or perforated shapes.

• Requirements for Reporting
  Test reports must specify:

  • Sample identification
  • Instrumentation details
  • Number and nature of measurements
  • Calculated average luminous reflectance factor and standard illuminant

Applications

• Light and Acoustic Ceiling Tile Manufacturers
  Determining the luminous reflectance factor is essential for product evaluation, quality control, and compliance with performance classifications, such as ASTM E1264.

• Lighting and Interior Design
  Designers use the reflectance data to model and optimize lighting design, energy efficiency, and the overall visual comfort of interior spaces, where ceilings and walls contribute significantly to ambient illumination.

• Building Codes and Sustainability
  Complying with standards like ASTM E1477 supports adherence to building and energy codes, and provides data for certification processes under green building rating systems that emphasize both acoustical and lighting efficiency.

• Architectural Consulting and Specification
  The standard ensures architects and engineers specify materials with known, predictable lighting performance, aiding in the design of spaces that are both acoustically and visually effective.

Related Standards

• ASTM E1264: Classification for Acoustical Ceiling Products, which references ASTM E1477 for luminous reflectance factor evaluation.
• ASTM E284: Terminology of Appearance, provides definitions relevant to the reflectance and measurement process.
• ASTM E308: Practice for Computing the Colors of Objects by the CIE System, aids in the calculation of luminous reflectance factors.
• ASTM E1164: Practice for Obtaining Spectrometric Data for Object-Color Evaluation, underpins sample preparation and measurement.
• ASTM E1331/E1347: Additional methods for reflectance and color measurement using hemispherical geometry and colorimetry.

By adhering to ASTM E1477, users ensure precise, reproducible, and internationally accepted practice in measuring the luminous reflectance factor of acoustical materials, supporting better lighting decisions and product performance in the built environment.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1477 −98a (Reapproved 2022)
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 3.1.1 Definitions of appearance terms in Terminology E284
are applicable to this test method.
1.1 This test method covers the measurement of the lumi-
3.1.2 integrating sphere, n—an optical device used either to
nous reflectance factor of acoustical materials for use in
collect flux reflected or transmitted from a specimen into a
predicting the levels of room illumination.
hemisphere or to provide isotropic irradiation of a specimen
1.2 This standard does not purport to address all of the
from a complete hemisphere, consisting of an approximately
safety concerns, if any, associated with its use. It is the
spherical cavity with apertures (ports) for admitting and
responsibility of the user of this standard to establish appro-
detecting flux, and usually having additional apertures over
priate safety, health, and environmental practices and deter-
which sample and reference specimens are placed and for
mine the applicability of regulatory limitations prior to use.
including or excluding the specularly reflected components.
1.3 This international standard was developed in accor-
(E284)
dance with internationally recognized principles on standard-
3.1.3 luminous, adj—weighted according to the spectral
ization established in the Decision on Principles for the
luminous efficiency function V(λ) of the CIE. (E284)
Development of International Standards, Guides and Recom-
3.1.4 reflectance factor, R, n—ratioofthefluxreflectedfrom
mendations issued by the World Trade Organization Technical
the specimen to the flux reflected from the perfect reflecting
Barriers to Trade (TBT) Committee.
diffuser under the same geometric and spectral conditions of
2. Referenced Documents
measurement. (E284)
2.1 ASTM Standards:
3.1.5 perfect reflecting diffuser—ideal reflecting surface that
E284 Terminology of Appearance
neither absorbs nor transmits light, but reflects light in a
E308 PracticeforComputingtheColorsofObjectsbyUsing
diffused manner with the radiance of the reflecting surface
the CIE System
being the same for all reflecting angles, regardless of the
E1164 PracticeforObtainingSpectrometricDataforObject-
angular distribution of the incident light. (E284)
Color Evaluation
4. Summary of Test Method
E1264 Classification for Acoustical Ceiling Products
E1331 Test Method for Reflectance Factor and Color by
4.1 Test specimens are measured for (total) luminous reflec-
Spectrophotometry Using Hemispherical Geometry
tance factor by standard color-measurement techniques using a
E1345 Practice for Reducing the Effect of Variability of
spectrophotometer, tristimulus (filter) colorimeter, or other
Color Measurement by Use of Multiple Measurements
reflectometer having a hemispherical optical measuring
E1347 Test Method for Color and Color-Difference Mea-
system, such as an integrating sphere. The specular component
surement by Tristimulus Colorimetry
isincludedtoprovidethetotalreflectancefactorcondition.The
instrument standard is referenced to the perfect reflecting
3. Terminology
diffuser. Luminous reflectance factor is calculated as CIE
3.1 Definitions:
tristimulus value Y for the CIE 1964 (10°) standard observer
and CIE standard illuminant D65 (daylight) or F2 (cool white
This test method is under the jurisdiction of ASTM Committee E12 on Color fluorescent).
and Appearance and is the direct responsibility of Subcommittee E12.02 on
Spectrophotometry and Colorimetry.
5. Significance and Use
Current edition approved Oct. 1, 2022. Published November 2022. Originally
ɛ1
5.1 Acoustical materials are often used as the entire ceiling
approved in 1992. Last previous edition approved in 2017 as E1477 – 98a (2017) .
DOI: 10.1520/E1477-98AR22.
of rooms and are therefore an important component of the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
lighting system. The luminous reflectance of all important
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
components must be known in order to predict the level of
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. illumination that will be obtained.
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E1477 − 98a (2022)
5.2 The reflecting properties of a surface are measured 7.3 Operate the reflectometer with the largest available area
relative to those of a standard reflector, the perfect reflecting of illumination or view. Measure at least three test specimens
diffuser, to provide a reflectance factor. The luminous reflec- randomly selected fro
...