ASTM E1331-96(2003)

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-Jul-2003
• ICS: 17.180.20 - Colours and measurement of light
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.02 - Spectrophotometry and Colorimetry

Relations

• Replaces: ASTM E1331-96 - Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry
• Effective Date: 10-Jul-2003
• Replaced By: ASTM E1331-04 - Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry
• Effective Date: 01-Jun-2004
• Referred By: ASTM D6441-05(2016) - Standard Test Methods for Measuring the Hiding Power of Powder Coatings
• Effective Date: 10-Jul-2003
• Referred By: ASTM C1650-14(2021) - Standard Practice for Instrumental Reflectance Measurement of Color for Flat Glass, Coated, and Uncoated
• Effective Date: 10-Jul-2003
• Referred By: ASTM D5531-17(2023) - Standard Guide for Preparation, Maintenance, and Distribution of Physical Product Standards for Color and Geometric Appearance of Coatings
• Effective Date: 10-Jul-2003
• Referred By: ASTM D2066-07(2020) - Standard Test Methods for Relative Tinting Strength of Paste-Type Printing Ink Dispersions
• Effective Date: 10-Jul-2003
• Referred By: ASTM D6290-19 - Standard Test Method for Color Determination of Plastic Pellets
• Effective Date: 10-Jul-2003
• Referred By: ASTM D8163-18(2023) - Standard Test Method for Determination of Strength of Colorants and Bases for Architectural, Marine, Maintenance, Commercial, and Industrial Coatings
• Effective Date: 10-Jul-2003
• Referred By: ASTM D7856-21 - Standard Specification for Color and Appearance Retention of Solid and Variegated Color Plastic Siding Products using CIELab Color Space
• Effective Date: 10-Jul-2003
• 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-Jul-2003
• Referred By: ASTM D3134-15(2019) - Standard Practice for Establishing Color and Gloss Tolerances
• Effective Date: 10-Jul-2003
• Referred By: ASTM E2387-19 - Standard Practice for Goniometric Optical Scatter Measurements
• Effective Date: 10-Jul-2003
• 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-Jul-2003
• Referred By: ASTM C1510-01(2020) - Standard Test Method for Color and Color Difference of Whitewares by Abriged Spectrophotometry
• Effective Date: 10-Jul-2003
• Referred By: ASTM D5382-02(2017) - Standard Guide to Evaluation of Optical Properties of Powder Coatings
• 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 1331 – 96 (Reapproved 2003)
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 3.1.1 The definitions in Guide E 179, Terminology E 284,
and Practice E 1164 are applicable to this test method.
1.1 This test method describes the instrumental measure-
ment of the reflection properties and color of object-color
4. Summary of Test Method
specimens by the use of a spectrophotometer or spectrocolo-
4.1 This test method provides a procedure for measuring the
rimeter with a hemispherical optical measuring system, such as
reflectance factors of reflecting object-color specimens by
an integrating sphere.
using a spectrophotometer or spectrocolorimeter equipped with
1.2 The test method is suitable for use with most object-
a hemispherical optical measuring system such as an integrat-
color specimens. However, it should not be used for retrore-
ing sphere.
flective specimens or for fluorescent specimens when highest
4.2 This test method includes procedures for calibrating the
accuracy is desired. Specimens having intermediate-gloss sur-
instrument and for selecting specimens suitable for precision
faces should preferably not be measured by use of this
measurement.
geometry.
4.3 Most modern spectrophotometers have the capacity to
1.3 This standard does not purport to address all of the
compute the color coordinates of the specimen immediately
safety concerns, if any, associated with its use. It is the
following the measurement. When this is the case, the user
responsibility of the user of this standard to establish appro-
must select the color system, observer, and illuminant (Practice
priate safety and health practices and determine the applica-
E 308, Section 6).
bility of regulatory limitations prior to use.
5. Significance and Use
2. Referenced Documents
5.1 The most direct and accessible methods for obtaining
2.1 ASTM Standards:
the color coordinates of object colors are by instrumental
D 2244 Practice for Calculation of Color Differences from
2 measurement using spectrophotometers or colorimeters with
Instrumentally Measured Color Coordinates
either hemispherical or bidirectional optical measuring sys-
E 179 Guide for Selection of Geometric Conditions for
tems. This test method provides procedures for such measure-
Measurement of Reflection and Transmission Properties of
2 ment by reflectance spectrophotometry using a hemispherical
Materials
2 optical measuring system.
E 284 Terminology of Appearance
5.2 This test method is especially suitable for measurement
E 308 Practice for Computing the Colors of Objects by
2 of the following types of specimens for the indicated uses
Using the CIE System
(Guide E 179 and Practice E 805):
E 805 Practice for Identification of Instrumental Methods of
2 5.2.1 All types of object-color specimens to obtain data for
Color or Color-Difference Measurement of Materials
use in computer colorant formulation.
E 991 Practice for Color Measurement of Fluorescent
2 5.2.2 Object-color specimens for color assessment.
Specimens
5.2.2.1 For the measurement of plane-surface high-gloss
E 1164 Practice for Obtaining Spectrophotometric Data for
specimens, the specular component should generally be ex-
Object-Color Evaluation
cluded during the measurement.
3. Terminology 5.2.2.2 For the measurement of plane-surface intermediate-
gloss specimens and of textured-surface specimens, including
3.1 Definitions:
textiles, where the first-surface reflection component may be
distributed over a wide range of angles, measurement may be
This test method is under the jurisdiction of ASTM Committee E12 on
made with the specular component included, but the resulting
Appearance and is the direct responsibility of Subcommittee E12.02 on Spectro-
color coordinates may not correlate best with visual judgments
photometry and Colorimetry.
of the color. The use of bidirectional geometry, such as 45/0 or
Current edition approved July 10, 2003. Published July 2003. Originally
approved in 1990. Last previous edition approved in 1996 as E 1331 – 96.
0/45, may lead to better correlations.
Annual Book of ASTM Standards, Vol 06.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 1331 – 96 (2003)
5.2.2.3 For the measurement of plane-surface, low-gloss 8. Calibration and Verification
(matte) specimens, the specular component may either be
8.1 Set the instrument for inclusion or exclusion of the
excluded or included, as no significant difference in the results
specular component of reflection; set the same as will be used
should be apparent.
in 8.4 (if carried out) or 9.1.
5.2.3 Specimens with bare metal surfaces for color assess- 8.2 Calibrate or verify the calibration of the following
ment. For this application, the specular component should
(Practice E 1164, Section 9):
generally be included during the measurement. 8.2.1 Zero setting of the reflectance scale (mandatory),
8.2.2 Wavelength scale (recommended), and
5.3 This test method is not recommended for measurement
8.2.3 Stray-light level (optional).
of the following types of specimens, for which the use of
8.3 Calibrate the full-scale value of the reflectance scale of
bidirectional measurement geometry (0/45 or 45/0) is prefer-
the instrument by use of the white reflectance standard (man-
able (Guide E 179):
datory). Follow the instrument manufacturer’s instructions.
5.3.1 Object-color specimens of intermediate gloss,
8.4 Verify the accuracy of the instrumental data by measure-
5.3.2 Retroreflective specimens, and
ment of a series of verification standards (recommended)
5.3.3 Fluorescent specimens (Practice E 991).
(Practice E 1164, 9.5). Select the appropriate color scales,
5.3.3.1 When there is doubt as to whether the specular observer, and illuminant for the computation of
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