The effect of orientation and latitude on the solar radiation received by test panels and fences during weathering studies

One of the main agents causing degradation of organic materials exposed outdoors is solar radiation, which gives rise to photo-oxidation reactions. Various aspects of the solar radiation received by surfaces of different orientations on clear days at several latitudes are examined. For small-scale exposure testing an equator-facing surface sloping at 45° to the horizontal is recommended at all latitudes. If exposure testing with vertical panels is required, east or west-facing surfaces are recommended within the tropics, and equator-facing surfaces at higher latitudes.