ASTM E1477-98a (2022) PDF

Full title and description

Standard Test Method for Luminous Reflectance Factor of Acoustical Materials by Use of Integrating-Sphere Reflectometers — a short, procedure-focused ASTM test method that specifies how to measure the total (including specular) luminous reflectance factor of acoustical materials using integrating-sphere type reflectometers and equivalent hemispherical optical measurement systems.

Abstract

This test method defines the measurement of luminous reflectance factor (CIE Y) of acoustical materials to assist in predicting room illumination levels. Measurements are made with integrating-sphere reflectometers, spectrophotometers, or tristimulus colorimeters referenced to a perfect reflecting diffuser; the specular component is included to report total reflectance. The method references CIE observers and standard illuminants for computation.

General information

• Status: Active (current edition published/reissued 2022).
• Publication date: October 1, 2022 (E1477‑98a (2022)).
• Publisher: ASTM International.
• ICS / categories: Colour and measurement of light; Acoustics in buildings (examples: ICS 17.180.20; 91.120.20).
• Edition / version: E1477‑98a (reissued/reapproved and published as the 2022 edition).
• Number of pages: 2 (concise test method).

Scope

This test method covers measurement of the luminous reflectance factor of acoustical materials for use in predicting room illumination levels. It applies to instruments with hemispherical measurement geometries (integrating-sphere reflectometers and equivalent systems), and includes procedures for reporting total (specular + diffuse) reflectance referenced to a perfect reflecting diffuser. It does not address safety practices, which remain the responsibility of the user.

Key topics and requirements

• Definition and measurement of luminous reflectance factor (CIE Y) for acoustical materials.
• Use of integrating-sphere reflectometers, spectrophotometers, or tristimulus colorimeters with hemispherical optical measuring systems.
• Inclusion of the specular component to report total reflectance.
• Reference to a perfect reflecting diffuser as the instrument standard.
• Computation using the CIE 1964 (10°) standard observer and standard illuminants (commonly D65 or F2).
• Short, practice-oriented reporting requirements suitable for product data and lighting prediction.

Typical use and users

Used by test laboratories, manufacturers of acoustical ceiling tiles and panels, lighting and lighting-design professionals, acoustical consultants, architects, and building code or specification writers who need reliable reflectance data to predict interior illumination and to specify acoustical materials in spaces where both acoustic and lighting performance are relevant.

Related standards

Closely related ASTM and referenced documents include appearance/measurement standards such as Terminology E284, and practices for reducing measurement variability (e.g., E1345); the method is referenced by or associated with other building and ceiling standards (for example, it is referenced by ceiling-product standards such as those for lay-in panels). The 2022 edition supersedes and reissues earlier reapprovals and errata editions (for example the 2017 reapproval/e1).

Keywords

acoustical materials, luminous reflectance factor, integrating sphere, reflectometer, spectrophotometer, CIE Y, specular component, total reflectance, room illumination.

FAQ

Q: What is this standard?

A: ASTM E1477‑98a (2022) is a short ASTM test method that specifies how to measure the luminous reflectance factor of acoustical materials using integrating-sphere reflectometers and equivalent hemispherical measurement systems.

Q: What does it cover?

A: It covers the measurement and reporting of total luminous reflectance (including the specular component) for acoustical materials, computation of CIE Y using standard observers/illuminants, and referencing instruments to a perfect reflecting diffuser.

Q: Who typically uses it?

A: Test labs, manufacturers of acoustical ceiling/absorptive products, lighting designers, acoustical and architectural consultants, and specification authors use this method to obtain consistent reflectance values for lighting predictions and product specifications.

Q: Is it current or superseded?

A: As of the 2022 reissue it is the current active edition (E1477‑98a (2022)), which reissues and updates earlier reapprovals and errata. Users should confirm any newer reissues after October 1, 2022 if absolute currency is required.

Q: Is it part of a series?

A: It is published under the jurisdiction of ASTM Committee E12 on Color and Appearance (Subcommittee E12.02 on Spectrophotometry and Colorimetry) and is part of a family of appearance and measurement methods addressing color, reflectance, and related instrument practices.

Q: What are the key keywords?

A: acoustical materials; luminous reflectance factor; integrating sphere; reflectometer; spectrophotometer; CIE Y; specular component; total reflectance.