ASTM E1331-96

Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry

SCOPE
1.1 This test method describes the instrumental measurement of the reflection properties and color of object-color specimens by the use of a spectrophotometer or spectrocolorimeter with a hemispherical optical measuring system, such as an integrating sphere.
1.2 The test method is suitable for use with most object-color specimens. However, it should not be used for retroreflective specimens or for fluorescent specimens when highest accuracy is desired. Specimens having intermediate-gloss surfaces should preferably not be measured by use of this geometry.
1.3 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

• Status: Historical
• Publication Date: 09-Jun-1996
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.02 - Spectrophotometry and Colorimetry

Relations

• Replaced By: ASTM E1331-96(2003) - Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry
• Effective Date: 10-Jul-2003
• Referred By: ASTM D3451-06(2017) - Standard Guide for Testing Coating Powders and Powder Coatings
• Effective Date: 10-Jun-1996
• Referred By: ASTM D6290-19 - Standard Test Method for Color Determination of Plastic Pellets
• Effective Date: 10-Jun-1996
• Referred By: ASTM D6531-00(2019) - Standard Test Method for Relative Tinting Strength of Aqueous Ink Systems by Instrumental Measurement
• Effective Date: 10-Jun-1996
• Referred By: ASTM E3125-17 - Standard Test Method for Evaluating the Point-to-Point Distance Measurement Performance of Spherical Coordinate 3D Imaging Systems in the Medium Range
• Effective Date: 10-Jun-1996
• Referred By: ASTM E313-20 - Standard Practice for Calculating Yellowness and Whiteness Indices from Instrumentally Measured Color Coordinates
• Effective Date: 10-Jun-1996
• Referred By: ASTM D5326-22 - Standard Test Method for Color Development in Tinted Latex Paints
• Effective Date: 10-Jun-1996
• Referred By: ASTM E2938-15 - Standard Test Method for Evaluating the Relative-Range Measurement Performance of 3D Imaging Systems in the Medium Range
• Effective Date: 10-Jun-1996
• Referred By: ASTM E1247-12(2017) - Standard Practice for Detecting Fluorescence in Object-Color Specimens by Spectrophotometry
• Effective Date: 10-Jun-1996
• Referred By: ASTM D2805-11(2023) - Standard Test Method for Hiding Power of Paints by Reflectometry
• Effective Date: 10-Jun-1996
• Referred By: ASTM E805-22 - Standard Practice for Identification of Instrumental Methods of Color or Color-Difference Measurement of Materials
• Effective Date: 10-Jun-1996
• Referred By: ASTM D7990-21 - Standard Test Method for Using Reflectance Spectra to Produce an Index of Temperature Rise in Polymeric Siding
• Effective Date: 10-Jun-1996
• Referred By: ASTM E179-17(2022) - Standard Guide for Selection of Geometric Conditions for Measurement of Reflection and Transmission Properties of Materials
• Effective Date: 10-Jun-1996
• Referred By: ASTM D6441-05(2016) - Standard Test Methods for Measuring the Hiding Power of Powder Coatings
• Effective Date: 10-Jun-1996
• Referred By: ASTM D2066-07(2020) - Standard Test Methods for Relative Tinting Strength of Paste-Type Printing Ink Dispersions
• Effective Date: 10-Jun-1996

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 1331 – 96
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
Reflectance Factor and Color by Spectrophotometry Using
Hemispherical Geometry
This standard is issued under the fixed designation E 1331; 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 and Practice E 1164 are applicable to this test method.
1.1 This test method describes the instrumental measure-
4. Summary of Test Method
ment of the reflection properties and color of object-color
4.1 This test method provides a procedure for measuring the
specimens by the use of a spectrophotometer or spectrocolo-
reflectance factors of reflecting object-color specimens by
rimeter with a hemispherical optical measuring system, such as
using a spectrophotometer or spectrocolorimeter equipped with
an integrating sphere.
a hemispherical optical measuring system such as an integrat-
1.2 The test method is suitable for use with most object-
ing sphere.
color specimens. However, it should not be used for retrore-
4.2 This test method includes procedures for calibrating the
flective specimens or for fluorescent specimens when highest
instrument and for selecting specimens suitable for precision
accuracy is desired. Specimens having intermediate-gloss sur-
measurement.
faces should preferably not be measured by use of this
4.3 Most modern spectrophotometers have the capacity to
geometry.
compute the color coordinates of the specimen immediately
1.3 This standard does not purport to address all of the
following the measurement. When this is the case, the user
safety concerns, if any, associated with its use. It is the
must select the color system, observer, and illuminant (Practice
responsibility of the user of this standard to establish appro-
E 308, Section 6).
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5. Significance and Use
5.1 The most direct and accessible methods for obtaining
2. Referenced Documents
the color coordinates of object colors are by instrumental
2.1 ASTM Standards:
measurement using spectrophotometers or colorimeters with
D 2244 Test Method for Calculation of Color Differences
2 either hemispherical or bidirectional optical measuring sys-
from Instrumentally Measured Color Coordinates
tems. This test method provides procedures for such measure-
E 179 Guide for Selection of Geometric Conditions for
ment by reflectance spectrophotometry using a hemispherical
Measurement of Reflection and Transmission Properties of
2 optical measuring system.
Materials
2 5.2 This test method is especially suitable for measurement
E 284 Terminology Relating to Appearance of Materials
of the following types of specimens for the indicated uses
E 308 Practice for Computing the Colors of Objects by
(Guide E 179 and Practice E 805):
Using the CIE System
5.2.1 All types of object-color specimens to obtain data for
E 805 Practice for Identification of Instrumental Methods of
use in computer colorant formulation.
Color or Color-Difference Measurement of Materials
5.2.2 Object-color specimens for color assessment.
E 991 Practice for Color Measurement of Fluorescent
5.2.2.1 For the measurement of plane-surface high-gloss
Specimens
specimens, the specular component should generally be ex-
E 1164 Practice for Obtaining Spectrophotometric Data for
cluded during the measurement.
Object-Color Evaluation
5.2.2.2 For the measurement of plane-surface intermediate-
3. Terminology gloss specimens and of textured-surface specimens, including
textiles, where the first-surface reflection component may be
3.1 Definitions:
distributed over a wide range of angles, measurement may be
3.1.1 The definitions in Guide E 179, Terminology E 284,
made with the specular component included, but the resulting
color coordinates may not correlate best with visual judgments
This test method is under the jurisdiction of ASTM Committee E-12 on
of the color. The use of bidirectional geometry, such as 45/0 or
Appearance and is the direct responsibility of Subcommittee E12.02 on Spectro-
0/45, may lead to better correlations.
photometry and Colorimetry.
Current edition approved June 10, 1996. Published August 1996. Originally
5.2.2.3 For the measurement of plane-surface, low-gloss
published as E 1331 – 90. Last previous edition E 1331 – 90.
(matte) specimens, the specular component may either be
Annual Book of ASTM Standards, Vol 06.01.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 1331
excluded or included, as no significant difference in the results (Practice E 1164, Section 9):
should be apparent.
8.2.1 Zero setting of the reflectance scale (mandatory),
5.2.3 Specimens with bare metal surfaces for color assess-
8.2.2 Wavelength scale (recommended), and
ment. For this application, the specular component should
8.2.3 Stray-light level (optional).
generally be included during the measurement.
8.3 Calibrate the full-scale value of the reflectance scale of
5.3 This test method is not recommended for measurement
the instrument by use of the white reflectance standard (man-
of the following types of specimens, for which the use of
datory). Follow the instrument manufacturer’s instructions.
bidirectional measurement geometry (0/45 or 45/0) is prefer-
8.4 Verify the accuracy of the instrumental data by measure-
able (Guide E 179):
ment of a series of verification standards (recommended)
5.3.1 Object-color specimens of intermediate gloss,
(Practice E 1164, 9.5). Select the appropriate color scales,
5.3.2 Retroreflective specimens, and
observer, and illuminant for the computation of color coordi-
5.3.3 Fluorescent specimens (Practice E 991).
nates before measurement.
5.3.3.1 When there is doubt as to whether the specular
compone
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