UV Accelerated Weathering Tester: Your Guide to Its Features and Uses The UV Accelerated Weathering Tester (model GT-C29) is a professional accelerated uv testing equipment widely used to simulate outdoor sunlight, rain, dew and other natural weathering environments. The harm includes color fading, discoloring, chalkiness, cracking, muddy, bubble, embrittlement, intensity, recession, oxidation etc...