ASTM E179-96

Standard Guide for Selection of Geometric Conditions for Measurement of Reflection and Transmission Properties of Materials

SCOPE
1.1 This guide is intended for use in selecting terminology, measurement scales, and instrumentation for describing or evaluating such appearance characteristics as glossiness, opacity, lightness, transparency, and haziness in terms of reflected or transmitted light. This guide does not consider the spectral variations responsible for color, but the geometric variables described herein can importantly affect instrumentally measured values of color. This guide is general in scope rather than specific as to instrument or material.

General Information

• Status: Historical
• Publication Date: 09-Nov-1996
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.03 - Geometry

Relations

• Replaced By: ASTM E179-96(2003) - Standard Guide for Selection of Geometric Conditions for Measurement of Reflection and Transmission Properties of Materials (Withdrawn 2012)
• Effective Date: 10-Jan-2003
• Referred By: ASTM E1349-06(2022) - Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Bidirectional (45°:0° or 0°:45°) Geometry
• Effective Date: 10-Nov-1996
• Referred By: ASTM E284-22 - Standard Terminology of Appearance
• Effective Date: 10-Nov-1996
• Referred By: ASTM D2205-20 - Standard Guide for Selection of Tests for Traffic Paints
• Effective Date: 10-Nov-1996
• Referred By: ASTM D4960-20 - Standard Test Method for Evaluation of Color for Thermoplastic Pavement Marking Materials
• Effective Date: 10-Nov-1996
• Referred By: ASTM D5386-16 - Standard Test Method for Color of Liquids Using Tristimulus Colorimetry
• Effective Date: 10-Nov-1996
• Referred By: ASTM C1649-14(2021) - Standard Practice for Instrumental Transmittance Measurement of Color for Flat Glass, Coated and Uncoated
• Effective Date: 10-Nov-1996
• Referred By: ASTM D6290-19 - Standard Test Method for Color Determination of Plastic Pellets
• Effective Date: 10-Nov-1996
• Referred By: ASTM E2301-12(2022) - Standard Test Method for Daytime Colorimetric Properties of Fluorescent Retroreflective Sheeting and Marking Materials for High Visibility Traffic Control and Personal Safety Applications Using 45°:Normal Geometry
• Effective Date: 10-Nov-1996
• Referred By: ASTM D5548-13(2020) - Standard Guide for Evaluating Color Transfer or Color Loss of Dyed Fabrics in Laundering (Not Suitable for Detergent or Washing Machine Rankings)
• Effective Date: 10-Nov-1996
• Referred By: ASTM E1348-22 - Standard Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical Geometry
• Effective Date: 10-Nov-1996
• Referred By: ASTM C1650-14(2021) - Standard Practice for Instrumental Reflectance Measurement of Color for Flat Glass, Coated, and Uncoated
• Effective Date: 10-Nov-1996
• Referred By: ASTM E430-23 - Standard Test Methods for Measurement of Gloss of High-Gloss Surfaces by Abridged Goniophotometry
• Effective Date: 10-Nov-1996
• Referred By: ASTM D8087-18 - Standard Test Method for Color of Maleic Anhydride in the Molten State and After Heating (Platinum-Cobalt Scale) Using Tristimulus Colorimetry
• Effective Date: 10-Nov-1996
• Referred By: ASTM C1510-01(2020) - Standard Test Method for Color and Color Difference of Whitewares by Abriged Spectrophotometry
• Effective Date: 10-Nov-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 179 – 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 Guide for
Selection of Geometric Conditions for Measurement of
Reflection and Transmission Properties of Materials
This standard is issued under the fixed designation E 179; 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.
INTRODUCTION
This is a guide describing the selecting of geometric conditions of measurement of appearance
attributes such as color, gloss, reflectance, opacity, and transmittance. It includes a selection of
numerical scales for appearance attributes other than color.
In describing appearance, wavelength (or spectral) variability is primarily responsible for color,
while geometric (or directional) selectivity is primarily responsible for gloss, luster, translucency, and
like attributes. However, geometric conditions not only affect geometric variables such as gloss and
transparency, but also affect color, diffuse reflectance, and transmittance. Likewise spectral conditions
can affect the measurement of geometric attributes of appearance. Therefore both the spectral and
geometric conditions of measurement must be identified in specifying an appearance attribute of a
specimen.
This guide describes the selection of geometric conditions and as a consequence should help
improve agreement in these measurements as well as providing useful guidance in resolving
differences between spectral-type measurements that are related to geometry.
1. Scope Whitewares and Related Products
D 523 Test Method for Specular Gloss
1.1 This guide is intended for use in selecting terminology,
D 1003 Test Method for Haze and Luminous Transmittance
measurement scales, and instrumentation for describing or
of Transparent Plastics
evaluating such appearance characteristics as glossiness, opac-
D 1455 Test Method for 60-deg Specular Gloss of Emulsion
ity, lightness, transparency, and haziness in terms of reflected
Floor Polish
or transmitted light. This guide does not consider the spectral
D 1494 Test Method for Diffuse Light Transmission Factor
variations responsible for color, but the geometric variables
of Reinforced Plastics Panels
described herein can importantly affect instrumentally mea-
D 1746 Test Method for Transparency of Plastic Sheeting
sured values of color. This guide is general in scope rather than
D 1834 Test Method for 20-deg Specular Gloss of Waxed
specific as to instrument or material.
Paper
2. Referenced Documents D 4039 Test Method for Reflection Haze of High-Gloss
Surfaces
2.1 ASTM Standards:
D 4061 Test Method for Retroreflectance of Horizontal
C 346 Test Method for 45-deg Specular Gloss of Ceramic
Coatings
Materials
E 97 Test Method for Directional Reflectance Factor, 45-
C 347 Test Method for Reflectance, Reflectivity, and Coef-
deg, 0-deg, of Opaque Specimens by Broad-Band Filter
ficient of Scatter of White Porcelain Enamels
Reflectometry
C 523 Test Method for Light Reflectance of Acoustical
E 167 Practice for Goniophotometry of Objects and Mate-
Materials by the Integrating Sphere Reflectometer
rials
C 584 Test Method for Specular Gloss of Glazed Ceramic
E 284 Terminology of Appearance
E 429 Test Method for Measurement and Calculation of
This guide is under the jurisdiction of ASTM Committee E-12 on Appearance
and is the direct responsibility of Subcommittee E12.03 on Geometry. Annual Book of ASTM Standards, Vol 15.02.
Current edition approved Nov. 10, 1996. Published February 1997. Originally Annual Book of ASTM Standards, Vol 06.01.
published as E 179 – 61 T. Last previous edition E 179 – 91a. Annual Book of ASTM Standards, Vol 08.01.
2 8
Annual Book of ASTM Standards, Vol 02.05. Annual Book of ASTM Standards, Vol 15.04.
3 9
Discontinued; see 1990 Annual Book of ASTM Standards, Vol 02.05. Annual Book of ASTM Standards, Vol 08.04.
4 10
Discontinued; see 1991 Annual Book of ASTM Standards, Vol 14.02. Annual Book of ASTM Standards, Vol 05.01.
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 179
Reflecting Characteristics of Metallic Surfaces Using Inte- ena can occur. Part of the light may be reflected, part may be
grating Sphere Instruments transmitted, and part may be absorbed. This guide deals with
E 430 Method for Measurement of Gloss of High Gloss the reflected and transmitted light and the selection of geomet-
Surfaces by Goniophotometry ric conditions for its measurement.
E 808 Practice for Describing Retroreflection 4.2 An idealization of the light reflected and transmitted by
E 809 Practice for Measuring Photometric Characteristics a material is shown in Fig. 1. Fig. 2 illustrates luminance
of Retroreflectors distributions more like those actually encountered in practice.
E 810 Test Method for Coefficient of Retroreflection of
5. Types of Measurement Scales
Retroreflective Sheeting
5.1 Type of Scale—The terms defined in 3.1.6-3.1.8 to may
E 811 Practice for Measuring Colorimetric Characteristics
be further identified by a preceding adjective, such as specular,
of Retroreflectors Under Nighttime Conditions
regular, diffuse, total, or directional, thereby identifying the
E 991 Practice for Color Measurement of Fluorescent
basis for the measurement scale. The significance of each of
Specimens
these adjectives is as follows:
E 1164 Practice for Obtaining Spectrophotometric Data for
5.1.1 regular—indicates that only light that has been re-
Object-Color Evaluation
flected or transmitted without scattering or diffusion is included
E 1767 Practice for Specifying the Geometry of Observa-
for measurement. When a specimen scatters or diffuses the
tions and Measurements to Characterize the Appearance of
incident light on reflection or transmission, the values obtained
Materials
will depend on the angular size of the illuminator and receiver
F 768 Method for Specular Reflectance and Transmittance
used in the measurement.
Measurements of Optically Flat-Coated and Non-Coated
5.1.2 specular—indicates that only the light that is mirror-
Specimens
reflected is included for measurement. The CIE prefers the
2.2 CIE Publications:
modifier regular instead of specular although specular reflec-
CIE Publication No. 15.2, Colorimetry, second edition 1986
tance is recognized. Specular has also sometimes been used to
CIE Publication No. 17.4, International Lighting Vocabu-
refer to regular transmittance. This is a misnomer because
lary, fourth edition, 1987
specular refers to a mirror.
CIE Publication No. 38, Radiometric and Photometric Char-
5.1.3 diffuse—indicates that only the light reflected or
acteristics of Materials and Their Measurement, 1977
transmitted in directions other than the specular or regular
3. Terminology
direction is included in the measurement.
3.1 Definitions:
NOTE 1—The differences between the concepts of regular and diffuse
3.1.1 flux (radiant), F—the time rate of flow of radiant
components of reflection and transmission are shown in Table 1.
energy; radiant power (Terminology E 284).
5.1.4 total—indicates that the light reflected or transmitted
3.1.2 incident flux, F —flux incident on the specimen at a
i
in all directions is included for measurement.
specified illumination angle and aperture angle.
5.1.5 directional—indicates that the light reflected or trans-
3.1.3 reflected flux, F —flux reflected from the specimen at
r
mitted in specified directions only is included for measure-
a specified viewing angle and aperature angle.
ment. Directional values depend on the illumination and
3.1.4 reference reflected flux, F —flux reflected from a
r.r
viewing angles and refer to light reflected or transmitted in
reference standard of reflectance, illuminated and viewed in the
directions that differ moderately from the centroid direction or
same manner as the specimen under consideration.
axis of the beam.
3.1.5 transmitted flux, F —flux transmitted through the
t
specimen at a specified viewing angle and field angle.
6. Geometric Directions of Incidence and Viewing
3.1.6 reflectance, r—ratio of the reflected flux to the inci-
6.1 Geometric directions may be identified by preceding the
dent flux defined as r5F / F .
r i
adjective with the angular directions, by including a detailed
3.1.7 reflectance factor, R—ratio of the reflected flux to the
geometric description, or by placing after the symbols a
reference reflected flux defined as R5F / F .
r r.r
subscript that represents the measurement condition.
3.1.8 transmittance, t—ratio of the transmitted flux to the
incident flux defined as t5F / F .
t i
3.1.8.1 Discussion—A companion term, transmittance fac-
tor, is not normally used in the measurement of appearance
attributes.
3.1.9 For other definitions see Terminology E 284 and CIE
Publication Nos. 17.4 and 38.
4. Summary of Guide
4.1 When light impinges upon a material, several phenom-
Discontinued; see 1995 Annual Book of ASTM Standards, Vol 06.01.
Information on how to obtain CIE documents should be requested from the
U.S. National Committee, CIE, c/o Radiometric Physics Division, National Institute FIG. 1 Idealizations of Reflection and Transmission Phenomena,
of Standards and Technology, Bldg. 220, Room B-306, Gaithersburg, MD 20899. Showing Components
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 179
6.4 azimuthal angle, h—the angle between the plane con-
taining the illuminator axis and the specimen normal and the
plane containing the receiver axis and the specimen normal.
Unless an azimuthal angle is specified, the illuminator axis, the
specimen normal, and the receiver axis are taken to be in the
same plane.
6.5 rotation angle, e—the angle indicating the orientation of
the test specimen when it is rotated in its own plane. The
orientation of the specimen is considered to be part of the
specimen description in this guide (see 10.2.7).
6.6 Complete geometric specifications are necessary for
measuring such geometrically dependent factors as gloss,
transparency, and haze. For ideally specular or ideally regular
or diffuse reflection or transmission, specification of only the
directions of illumination and view is usually adequate.
7. Measured Quantities
7.1 The following quantities, defined and described in more
FIG. 2 Representations of Actual Reflection and Transmission
detail in the Illuminating and Viewing Conditions section of
Phenomena with Mixtures of Components
Practice E 1164 and in C
...