This part of ISO 4892 specifies methods for exposing specimens to fluorescent UV radiation and water in apparatus to designed reproduce the weathering effects that occur when materials are exposed in actual end-use environments to daylight, or to daylight through window glass.
The specimens are exposed to fluorescent UV lamps under controlled environmental conditions (temperature, humidity and/or water). Different types of fluorescent UV lamp may be used to meet all the requirements for testing different materials.