This Part of EN 13523 specifies the procedures for determining the dry film thickness of an organic coating on a metallic substrate (coil coating). Four appropriate methods are given in this Part of EN 13523: a) magnetic induction; b) eddy current; c) micrometer; d) optical. The methods are applicable only to products with smooth and flat substrates but the coating itself may be textured. In that case, for methods a and b the average of a series of readings will represent an average of the thickness of the organic coating, while method c will give the maximum thickness and method d can provide the minimum, maximum and average thickness. Non-destructive continuous-web methods on measurement of dry-film thickness (see EN ISO 2808) are not dealt with.