ČSN EN 13523-15   (038761) Kontinuálně lakované kovové pásy - Zkušební metody - Část 15: Metamerie

Anotace textu normy ČSN EN 13523-15   (038761)

This part of EN 13523 defines terms of the procedure for determining the metamerism of a colour match of an organic coating on a metallic substrate.

When two colour specimens have identical spectral reflection curves, they are matching under any illuminant irrespective of its spectral characteristics. This is termed a ´spectral match´. It is also possible for two colour specimens having different spectral reflection curves to match visually under a given light source but not to match under another light source with different spectral characteristics, such matches are termed ´metameric´.

One quantitative description of metamerism is the so-called ´metamerism index´.

The information of the metamerism index is of limited value where dE (instrumental colour difference for a given illuminant, see EN 13523-3) is > 0,5. The metamerism index is not suited for determining the absolute colour difference or colour constancy of a given specimen at change of illuminant.

The colour difference under the reference illuminant is to be measured in colour coordinates L*, a* and b* (see EN 13523-3).

Excluded from this method are organic coatings producing fluorescence and/or which are multicoloured, pearlescent or metallic.