The three radiant energy weathering procedures described in these test methods are intended to determine the effects of extended outdoor exposure-induced stress that may occur during service life of photovoltaic modules. Because most accelerated weathering devices are not large enough to accept full-sized photovoltaic modules, the simulated weathering test procedures may be suitable only for smaller test modules. The construction of smaller test modules should be as close in design and function as possible to full-size modules. The three solar weathering test methods are as follows: Procedure A -Natural sunlight, real-time exposure testing, Procedure B -Accelerated exposure testing concentrated natural sunlight, and 1.2.3 Procedure C -Accelerated exposure testing using simulated sunlight. The test methods do not provide for weathering studies on individual components of photovoltaic modules. There is no similar or equivalent ISO Standard. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.