scope:

NEN-EN 13523-3 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: a) instrumental colour difference measurement using a tristimulus colorimeter; 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.