The QUV accelerated weathering tester reproduces the damage caused by sunlight, rain and dew. In a few days or weeks, the QUV UV tester can reproduce the damage that occurs over months or years outdoors. To simulate outdoor weathering, the QUV accelerated tester exposes materials to alternating cycles of UV light and moisture at controlled, elevated temperatures. It simulates the effects of natural sunlight and artificial irradiance using special fluorescent UV lamps in the UVA, UVB, and UVC portions of the spectrum. It simulates dew and rain with condensing humidity and/or water spray. The QUV accelerated weathering tester is the simplest, most reliable, and easiest to use weathering tester available. With thousands of testers in use worldwide, it is the world's most widely used weathering tester.