This Part of this European Standard specifies a grid rating system that provides a means of defining levels of performance of anodic oxidation coatings on aluminium and its alloys that have been subjected to corrosion tests.
This rating system is applicable to pitting corrosion resulting from
- accelerated tests;
- exposure to corrosive environments;
- practical service tests.
It takes into account only pitting corrosion of the basis metal resulting from penetration of the protective anodic oxidation coating.
NOTE 1 A related standard, EN 12373-18:2001, describes a similar rating system based on chart scales.
NOTE 2 The grid rating system is frequently used for rating the results of short term corrosion tests on relatively thin anodic oxidation coatings such as those used in the automotive industry.