ASTM E2539-12

This document is not anASTM standard and is intended only to provide the user of anASTM 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:E2539–08 Designation: E2539 – 12
Standard Practice for
1
Multiangle Color Measurement of Interference Pigments
This standard is issued under the fixed designation E2539; 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.
INTRODUCTION
Objects that exhibit a change in color with different angles of illumination and view are said to be
“gonioapparent.” The tristimulus colorimetric values of gonioapparent objects are derived using the
spectral reflectance factors obtained from spectrometric measurements or colorimetric measurements
atvariousanglesofilluminationanddetection.Thetristimuluscolorimetricvaluesarecomputedusing
the spectral reflectance factors of the object, the CIE Standard Observer, and the spectral power
distribution of the illuminant, as described in Practice E308. This Practice, E2539, specifies the color
measurement of interference pigments at various illumination and detection angles.
1. Scope
1.1 This practice covers the instrumental requirements and required parameters needed to make instrumental color
measurements of thin film interference pigments. This practice is designed to encompass interference pigments used in
architectural applications, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and other
applications.
1.2 Characterization of the optical behavior of materials colored with interference pigments requires measurement at multiple
angles of illumination and detection.
1.3 Data taken utilizing this practice are quantitative and are appropriate for quality control of interference pigment color.
1.4 The measurement results are usually expressed as reflectance factors, tristimulus color values, or as CIE L*a*b* color
coordinates and color difference.
1.5 The totality of data taken may not be necessary for evaluating mixtures also containing non-interference pigments. The
committeeisinvestigatingandevaluatingtheappropriatenessofthispracticeforthosematerials.Itistheresponsibilityoftheusers
to determine the applicability of this practice for their specific applications.
1.6 Interference pigments are typically evaluated for color and color appearance in a medium, such as paint or ink. The
gonioapparent effect depends strongly on the physical and chemical properties of the medium. Some of the properties affecting
color and color appearance include vehicle viscosity, thickness, transparency, and volume solids. As a general rule, for quality
control purposes, interference pigments are best evaluated in a masstone product form. In some cases this product form may be
the final product form, or more typically a qualified simulation of the intended product form (such as a paint drawdown) that in
terms of color and appearance correlates to final product application.
1.7 Thisstandarddoesnotaddresstherequirementsforcharacterizingmaterialscontainingmetalflakepigments.Measurements
of the optical characteristics of materials containing metal flake pigments are described in Practice E2194.
1.8 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.9 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.
2. Referenced Documents
2
2.1 ASTM Standards:
E284 Terminology of Appearance
E308 Practice for Computing the Colors of Objects by Using the CIE System
1
This practice is under the jurisdiction of ASTM Committee E12 on Color and Appearance and is the direct responsibility of Subcommittee E12.12 on Gonioapparent
Color.
Current edition approved Feb. 1, 2008. Published February 2008. DOI: 10.1520/E2539-08.
CurrenteditionapprovedApril1,2012.PublishedMay2012.Originallyapprovedin2008.Lastpreviouseditionapprovedin2008asE2539 - 08.DOI:10.1520/E2539-12.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States
...