n Tests designed to simulate, but at the same time to intensify and accelerate, the destructive action of natural outdoor weathering on coatings films. The tests involve exposure to artificially produced components of natural weather, e.g., light, heat, cold, water vapor, rain, etc., which are arranged and repeated in a given cycle. There is no universally accepted test, and different investigators use different cycles (Paint and coating testingmanual (Gardner-Sward handbook) (1995) MNL 17, 14th edn. ASTM, Conshohocken, PA). See Artificial Weathering.