ASTM C1650-14(2021)

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: C1650 −14 (Reapproved 2021)
Standard Practice for
Instrumental Reflectance Measurement of Color for Flat
Glass, Coated, and Uncoated
This standard is issued under the fixed designation C1650; 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 E1164 PracticeforObtainingSpectrometricDataforObject-
Color Evaluation
1.1 This practice provides guidelines for the instrumental
E1331 Test Method for Reflectance Factor and Color by
reflectance measurement of the color of flat, coated and
Spectrophotometry Using Hemispherical Geometry
uncoated glass. (See Terminology E284.)
2.2 CIE Standard:
1.2 The practice specifically excludes fluorescent and iri-
CIE 15:2004 Colorimetry, Third Edition
descent samples.
3. Summary of Practice
1.3 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
3.1 The reflected color of glass products, (see Guide E179)
standard.
is measured in reflectance specular included mode on a
CIE-conforming diffuse geometry instrument. (See Test
1.4 This standard does not purport to address all of the
Method E1331 and CIE 15:2004.) The glass color is expressed
safety concerns, if any, associated with its use. It is the
in CIE tristimulus values based on spectral transmittance
responsibility of the user of this standard to establish appro-
measurements over the full CIE spectral range of 350 to
priate safety, health, and environmental practices and deter-
780 nm with a maximum 10 nm band pass. (See CIE 15:2004
mine the applicability of regulatory limitations prior to use.
and Practice E308.) For color measurement, use of a truncated
1.5 This international standard was developed in accor-
spectral range of 400 to 700 nm is acceptable. (See CIE
dance with internationally recognized principles on standard-
15:2004.) Further information on the UV absorbing character-
ization established in the Decision on Principles for the
istics of the glass or glass coating, or both, may be determined
Development of International Standards, Guides and Recom-
by examining the spectral data in the 350 to 400 nm range. If
mendations issued by the World Trade Organization Technical
the instrument allows spectral measurement above 700 nm,
Barriers to Trade (TBT) Committee.
useful information on the IR reflectance characteristics of the
2. Referenced Documents
glass coating may also be determined. If coatings are present,
they can be opaque or partially reflective.
2.1 ASTM Standards:
D2244 Practice for Calculation of Color Tolerances and
4. Significance and Use
Color Differences from Instrumentally Measured Color
Coordinates 4.1 Colormeasurementquantifiesthecoatingcolorforglass
E179 Guide for Selection of Geometric Conditions for and is often related to coating thickness and composition as
Measurement of Reflection and Transmission Properties well as tinting used in the substrate glass. The user of this
of Materials document defines an acceptable range of color appropriate for
E284 Terminology of Appearance the end use. Typical quality concerns for the reflected color
E308 PracticeforComputingtheColorsofObjectsbyUsing measurement of coated glass products are an indication of
consistency in the coating process and verification of lot-to-lot
the CIE System
color consistency for end-user acceptance.
1 4.2 If the reflected color of a glass product is consistent
This practice is under the jurisdiction of ASTM Committee C14 on Glass and
Glass Products and is the direct responsibility of Subcommittee C14.11 on Optical
from lot-to-lot and within agreed supplier-buyer acceptance
Properties.
criteria, that product color is expected to be consistent and
Current edition approved July 1, 2021. Published July 2021. Originally approved
acceptable for end-use.
in 2007. Last previous edition approved in 2014 as C1650 – 14. DOI: 10.1520/
C1650-14R21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from U.S. National Committee of the CIE (International Commission
Standards volume information, refer to the standard’s Document Summary page on on Illumination), C/o Alan Laird Lewis, 282 E. Riding, Carlisle, MA 01741,
the ASTM website. http://www.cie-usnc.org.
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C1650 − 14 (2021)
5. Apparatus available from the manufacturer). Care should be taken to
visually inspect these standards for any significant visual
5.1 For color measurements, a CIE-conforming diffuse
abrasion and replace it if warranted.
geometry instrument capable of making reflectance measure-
8.4 As the stability characteristics of coated and non-coated
ments in the specular included mode is required.
glass are generally good, the user may, at their option, read and
5.2 A fixture device is required to consistently place the
record color values for a glass sam
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