ÖNORM EN ISO 877

This International Standard specifies methods of exposing plastics to solar radiation, either by direct exposure to natura1 weathering (Method A), to indirect solar radiation by modification of its spectral distribution with glass to simulate ageing of plastics behind building or automotive window glass (Method B), or to solar radiation intensified by the use of Fresnel mirrors to achieve acceleration of the weathering processes (Method C). The purpose is to assess changes produced after specified stages of such exposures. This International Standard specifies the general requirements for the apparatus and operating procedures for using the test methods described. Although this International Standard does not include direct weathering using black-box test fixtures, attention is drawn to this method of exposure testing of materials under conditions simulating their end-use temperatures. Methods B and C exclude the effects of weathering influences such as wind and rain, although the Method C apparatus used to produce intensified solar radiation is equipped to provide moisture in the form of water Spray. When comparing the results of exposure using Method C with results using Methods A and B, differences in specimen temperatures, ultraviolet radiant exposure levels and moisture deposition should be taken into account. Additionally, when comparing Method C exposures to Method B exposures, the glass or other transparent materials used as filters should be identical. Exposure results being compared should be for ultraviolet radiant exposure levels that agree closely with each other. This International Standard also specifies methods for determining radiation dosage. The methods are applicable to plastics materials of all kinds and to products and portions of products. NOTE 1 For the determination of changes in properties after exposure, see ISO 4582.