This part of ISO 877 provides information and general guidance on the selection and use of the methods of exposure to solar radiation described in detail in subsequent parts of ISO 877. These methods of exposure to solar radiation are applicable to plastics materials of all kinds as well as to products and portions of products. It also specifies methods for determining radiant exposure. It does not include direct weathering using black-box test fixtures, which simulate higher end-use temperatures in some applications. NOTE ASTM G 7 [1] and ASTM D 4141 [2] describe black-box exposure tests.