NBN EN 13523-3:2014

This part of EN 13523 specifies procedures for determining the instrumental colour difference (CIELAB) of an organic coating on a metallic substrate.
Establishing a standard as well as the magnitude of an acceptable colour difference are not covered by this method.
Two appropriate methods are given in this part of EN 13523:
a) instrumental colour difference measurement using a tristimulus colorimeter
b) instrumental colour difference measurement using a spectrophotometer or equivalent.
Care shall be taken when measuring e.g.
- textured surfaces
- fluorescent coatings
- metameric coatings
- multi-coloured, pearlescent, metallic or special colour effect coatings.
In order to determine whether metamerism is present, the metamerism index is determined (see EN 13523-15) and/ or a visual examination (see EN 13523-22) is performed with different artificial light sources.