BS EN 13523-3:2014

Coil coated metals. Test methods. Colour difference. Instrumental comparison | Status: Superseded, Withdrawn

1 Scope 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 methods are given in this part of EN 13523:

1. a) instrumental colour difference measurement using a tristimulus colorimeter;
2. b) instrumental colour difference measurement using a spectrophotometer or equivalent.

Care should 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.