ASTM D2805-11(2018)

Standard Test Method for Hiding Power of Paints by Reflectometry

SIGNIFICANCE AND USE
5.1 This is a precise instrumental method giving results having an absolute physical significance without reference to a comparison paint. It should be used when maximum precision and minimum subjectivity are required, as in testing specification coatings or evaluating the hiding efficiency of pigments.  
5.2 Hiding power Test Method D344 is visual instead of instrumental, and gives results that are relative to a material standard instead of absolute. It is less precise than Test Method D2805 but more closely aligned with practical painting procedures.
SCOPE
1.1 This test method covers the determination, without reference to a material paint standard, of the hiding power of air dry coatings with Y tristimulus values greater than 15 %. With appropriate modification, it can also be used to test baking finishes.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

General Information

• Status: Historical
• Publication Date: 31-Jan-2018
• ICS: 87.040 - Paints and varnishes
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.26 - Optical Properties

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D2805 − 11 (Reapproved 2018)
Standard Test Method for
1
Hiding Power of Paints by Reflectometry
This standard is issued under the fixed designation D2805; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
INTRODUCTION
2
Using equations derived from Kubelka-Munk turbid media theory (1-4) (see Annex A1), the
reflectance of a coating can be predicted for any film thickness from measurements made at only one.
On this basis several rapid and accurate test methods (5, 6) have been developed for determining
hiding power. In the past such test methods have been considered difficult due to complexities,
apparent and actual, in the treatment of data. The present test method has been simplified in this
respect, primarily by adapting it fully for computer calculations.
Although the use of broad-band reflectometry makes this test method theoretically valid only for
nonchromatic (white or gray) colors, good agreement has been obtained with chromatic paints as well.
This is undoubtedly because the experimental measurements are made fairly close to the hiding power
end point so that the Kubelka-Munk extrapolation and thus any associated error is relatively small.
This test method is therefore recommended without restriction as to color.
1. Scope 2. Referenced Documents
3
1.1 This test method covers the determination, without 2.1 ASTM Standards:
reference to a material paint standard, of the hiding power of D344 Test Method for Relative Hiding Power of Paints by
air dry coatings with Y tristimulus values greater than 15 %. the Visual Evaluation of Brushouts
With appropriate modification, it can also be used to test D1475 Test Method for Density of Liquid Coatings, Inks,
baking finishes. and Related Products
D3924 Specification for Standard Environment for Condi-
1.2 The values stated in SI units are to be regarded as
tioning and Testing Paint, Varnish, Lacquer, and Related
standard. No other units of measurement are included in this
4
Materials (Withdrawn 2016)
standard.
E284 Terminology of Appearance
1.3 This standard does not purport to address all of the
E1247 Practice for Detecting Fluorescence in Object-Color
safety concerns, if any, associated with its use. It is the
Specimens by Spectrophotometry
responsibility of the user of this standard to establish appro-
E1331 Test Method for Reflectance Factor and Color by
priate safety, health, and environmental practices and deter-
Spectrophotometry Using Hemispherical Geometry
mine the applicability of regulatory limitations prior to use.
E1347 Test Method for Color and Color-Difference Mea-
1.4 This international standard was developed in accor-
surement by Tristimulus Colorimetry
dance with internationally recognized principles on standard-
E1349 Test Method for Reflectance Factor and Color by
ization established in the Decision on Principles for the
Spectrophotometry Using Bidirectional (45°:0° or 0°:45°)
Development of International Standards, Guides and Recom-
Geometry
mendations issued by the World Trade Organization Technical
3. Terminology
Barriers to Trade (TBT) Committee.
3.1 Definitions—For definitions used in this test method, see
Terminology E284.
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, and Applications and is the direct responsibility of
3
Subcommittee D01.26 on Optical Properties. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 1, 2018. Published February 2018. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1969. Last previous edition approved in 2011 as D2805 – 11. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D2805-11R18. the ASTM website.
2 4
The boldface numbers in parentheses refer to the list of references at the end of The last approved version of this historical standard is referenced on
this standard. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D2805 − 11 (2018)
3.2 Definitions of Terms Specific to This Standard: 4.4 As an optional procedure the contrast ratio C at a
specified spreading rate H is calculated from R and S.
3.2.1 contrast ratio, n—the ratio of the reflectance of a film
C ∞
on a black substrate to that of an identical film on a white
5. Significance and Use
substrate.
5.1 T
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2805 − 11 D2805 − 11 (Reapproved 2018)
Standard Test Method for
1
Hiding Power of Paints by Reflectometry
This standard is issued under the fixed designation D2805; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
INTRODUCTION
2
Using equations derived from Kubelka-Munk turbid media theory (1-4) (see Annex A1), the
reflectance of a coating can be predicted for any film thickness from measurements made at only one.
On this basis several rapid and accurate test methods (5, 6) have been developed for determining
hiding power. In the past such test methods have been considered difficult due to complexities,
apparent and actual, in the treatment of data. The present test method has been simplified in this
respect, primarily by adapting it fully for computer calculations.
Although the use of broad-band reflectometry makes this test method theoretically valid only for
nonchromatic (white or gray) colors, good agreement has been obtained with chromatic paints as well.
This is undoubtedly because the experimental measurements are made fairly close to the hiding power
end point so that the Kubelka-Munk extrapolation and thus any associated error is relatively small.
This test method is therefore recommended without restriction as to color.
1. Scope
1.1 This test method covers the determination, without reference to a material paint standard, of the hiding power of air dry
coatings with Y tristimulus values greater than 15 %. With appropriate modification, it can also be used to test baking finishes.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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.
2. Referenced Documents
3
2.1 ASTM Standards:
D344 Test Method for Relative Hiding Power of Paints by the Visual Evaluation of Brushouts
D1475 Test Method for Density of Liquid Coatings, Inks, and Related Products
D3924 Specification for Standard Environment for Conditioning and Testing Paint, Varnish, Lacquer, and Related Materials
4
(Withdrawn 2016)
E284 Terminology of Appearance
E1247 Practice for Detecting Fluorescence in Object-Color Specimens by Spectrophotometry
E1331 Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry
E1347 Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.26 on Optical Properties.
Current edition approved June 1, 2011Feb. 1, 2018. Published June 2011February 2018. Originally approved in 1969. Last previous edition approved in 20032011 as
D2805 – 96a (2003).D2805 – 11. DOI: 10.1520/D2805-11.10.1520/D2805-11R18.
2
The boldface numbers in parentheses refer to the list of references at the end of this standard.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
4
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D2805 − 11 (2018)
E1349 Test Method for Reflectance Factor and Color by Spectrophotometry Using Bidirectional (45°:0° or 0°:45°) Geometry
3. Terminology
3.1 Definitions—For definitions used in this test method, see Terminology
...