3.1 Organic coatings on exterior exposure are subjected to attack by degrading elements of the weather, particularly ultraviolet light, oxygen, and water. This practice may be used for evaluating the protective behavior of polish film applied to a coating. This polish-coated coating is then exposed in an apparatus that produces ultraviolet radiation, temperature variation, and water condensation for a given time period.
3.2 No single light exposure apparatus, with or without water, can be specified as a direct simulation of natural exposure. This practice does not imply a specific correlation with outdoor exposure. It is, however, useful in screening the relative protective qualities of a polish within the test parameter.