The IEC 61345-1998 standard defines a test method for photovoltaic modules in an ultraviolet radiation environment to evaluate their resistance to ultraviolet radiation. The test is mainly for the polymer and protective layer in the component to ensure its durability under ultraviolet light at wavelengths of 280nm to 400nm. The standard requires optical aging or Miscellaneous pretreatment according to GB/T 9535 or GB/T 18911 before UV testing to ensure the accuracy and validity of the test results.