The standard defines two accelerated outdoor exposure test procedures for evaluating the weathering resistance of coatings: Procedure A (black box exposure) and Procedure C (Fresnel reflector rack exposure). These procedures provide a higher rate of degradation than normal outdoor exposure. Procedure A is suitable for materials under high temperature conditions, while Procedure C simulates a strong light environment through a condenser. The standard emphasizes that a single test cannot predict the long-term degradation rate. It is recommended to perform a multi-year, sexual repeability test to obtain accurate weathering resistance data. At the same time, comparison with control materials is used to improve the Reliability of test results.