Outdoor tests take too long, often stretching for several years.
Indoor devices can accelerate the testing process but do not always provide optimal results. Researchers at the National Institute of Standards and Technology have developed a spherical device that distributes UV radiation uniformly into 32 external specimen chambers, ensuring repeatability and reproducibility of test results. The device is calculated to accelerate UV exposure 30 to 65 times faster than natural solar exposure. Sealed quartz tube bulbs are arranged uniformly around an opening at the top. Microwave energy heats the gases inside the bulbs to form a high-temperature plasma.