ASTM E2194-12 - 1.4.2012
 
Significance and Use

Instrumental Measurement AnglesThis practice is designed to provide color data at specific measurement angles that can be utilized for quality control, color matching, and formulating in the characterization of metal flake pigmented materials.

MaterialsThis practice provides meaningful color information for metal flake pigmented materials. This practice has been tested and verified on paint and coatings, and the same principles should apply to plastics containing metallic flake. For materials containing pearlescent materials refer to Practice E2539.

UtilizationThis practice is appropriate for measurement and characterization of metal flake pigmented materials. These data may be used for quality control, incoming inspection, or color correction purposes.

Specimen RequirementsEven though a pair of specimens have the same color values at three angles, if there are differences in gloss, orange peel, texture, or flake orientation, they may not be a visual match.

Note 2—Information presented in this practice is based upon data taken on metallic materials coatings. Applicability of this practice to other materials should be confirmed by the user.

 
1. Scope

1.1 This practice covers the instrumental requirements, standardization procedures, material standards, and parameters needed to make precise instrumental measurements of the colors of gonioapparent materials. This practice is designed to encompass gonioapparent materials; such as, automotive coatings, paints, plastics, and inks.

1.2 This practice addresses measurement of materials containing metal flake and pigments. The measurement of materials containing metal flakes requires three angles of measurement to characterize the colors of the specimen. The optical characteristics of materials containing pearlescent and interference materials are not covered by this practice.

Note 1—Data taken by utilizing this practice are for gonio-appearance quality control purposes. This procedure may not necessarily supply appropriate data for spatial-appearance or pigment identification.

1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.4 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

E2539-14(2021)

Standard Test Method for Multiangle Color Measurement of Interference Pigments

Publication No. 15:2004

Colorimetry

E1708-20

Standard Practice for Electronic Interchange of Color and Appearance Data

E1345-98(2019)

Standard Practice for Reducing the Effect of Variability of Color Measurement by Use of Multiple Measurements

E805-22

Standard Practice for Identification of Instrumental Methods of Color or Color-Difference Measurement of Materials

E308-22

Standard Practice for Computing the Colors of Objects by Using the CIE System

E284-22

Standard Terminology of Appearance

ISO International Vocabulary of Basic and General Terms in Metrology (VIM)

LC-1017

Standards for Checking the Calibration of Spectrophotometers