This part of IEC 60068 specifies the methods of testing of equipment or components under simulated solar radiation conditions. This document is applicable to the equipment and components at the surface of the earth. The purpose of testing is to investigate to what extent the equipment or components are affected by simulated solar radiation in the presence of moisture to reproduce the weathering effects (temperature, humidity and/or wetting) that occur when they are exposed in actual end-use environments to daylight or to daylight filtered through window glass. In this standard there are two test methods, test method Sa: thermal effect test, and test method Sb: weathering test.