ASTM D3964-10(2020)

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: D3964 − 10 (Reapproved 2020)
Standard Practice for
Selection of Coating Specimens for Appearance
Measurements
This standard is issued under the fixed designation D3964; 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 For definitions of terms used in this practice, refer to
Terminology E284.
1.1 This practice provides a guide to selection of specimens
for appearance measurement by reflected light as well as a
4. Significance and Use
discussion of factors to be considered in their preparation for
measurement. Standardized selection and presentation proce-
4.1 Many of the specimens that are regularly submitted to
dures will assist in achieving agreement between evaluations
measurement depart in some degree from the ideal require-
carried out in different laboratories as well as helping to
ments. For this reason instrumental readings are affected
achieve better correlations between visual evaluations and
importantlybythemannerinwhichspecimensareselectedand
instrumental measurements.
presented for measurement. Reproducible measurements are
facilitated by standardization and control of test conditions.
NOTE 1—This standard is not a practice for preparation of test panels of
coatings; see Practices D823.
1.2 This standard does not purport to address all of the 5. General Requirements
safety concerns, if any, associated with its use. It is the
5.1 Selection—In making appearance measurements it is
responsibility of the user of this standard to establish appro-
important that the specimens selected be representative of the
priate safety, health, and environmental practices and deter-
material of interest. Once selected, the specimens must be
mine the applicability of regulatory limitations prior to use.
carefully examined to determine if they are suitable for
1.3 This international standard was developed in accor-
measurement, and if not, they must be cleaned or otherwise
dance with internationally recognized principles on standard-
prepared. Careful attention to these factors is necessary if the
ization established in the Decision on Principles for the
measurements are to be valid.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5.2 Specimen Size—The minimum size is dictated by the
Barriers to Trade (TBT) Committee.
size of the specimen port of the instrument to be used for
measurement. When an instrument provides a choice of speci-
2. Referenced Documents
men port sizes, use the largest port that can be completely
covered by the specimen. A large measured area helps to
2.1 ASTM Standards:
minimize the effect of any small area nonuniformity and is
D823 Practices for Producing Films of Uniform Thickness
therefore more likely to provide results that agree with the
of Paint, Coatings and Related Products on Test Panels
involuntary averaging that takes place when specimens are
E284 Terminology of Appearance
observed visually. In addition, a large specimen also permits
the operator to make measurements on several areas of the
3. Terminology
specimen when desired, thereby providing further specimen
3.1 Definitions:
averaging.
5.3 Opacity—For determination of gloss or color, an opaque
1 specimen shall be selected whenever possible. When the
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
Related Coatings, Materials, and Applications and is the direct responsibility of
specimen is translucent or transparent, the following practices
Subcommittee D01.26 on Optical Properties.
shall be implemented:
CurrenteditionapprovedJune1,2020.PublishedJuly2020.Originallyapproved
5.3.1 For Gloss Evaluation—The specimen shall preferably
in 1980. Last previous edition approved in 2015 as D3964 – 10 (2015). DOI:
10.1520/D3964-10R20.
be sufficiently thick that a secondary reflection from the back
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
or second surface of the specimen cannot enter the receptor
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
optics of the glossmeter. When thin transparent specimens
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. must be measured, adopt one of the following procedures:
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D3964 − 10 (2020)
5.3.1.1 Back the specimen with a light-absorbing material 7. Cleaning of Specimens
of the same refractive index as the specimen, and in optical
7.1 The specimen shall be clean. There should be no dirt,
contact with it.
dust, oil or foreign material on the surface that will affect the
5.3.1.2 Use an agreed-upon spe
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