This standard specifies the operating procedures for accelerated weathering testing of Coatings in open flame carbon arc installations to assess the durability of Coatings and related products under environmental factors such as light, heat and moisture. The tests simulate variations in the performance of Coatings under actual conditions of use, but do not involve special environmental effects such as atmospheric contamination, biological attack or saline water exposure. The standard emphasizes the use of the same carbon arc configuration to ensure conformity of inter-laboratory results, while recommending multiple repeability tests of test materials to obtain reliable data. Note that the test conditions and equipment operation described in this standard are critical to the accuracy of test results.