Ultraviolet (UV) light is radiation invisible to the human eye that can be harmful or beneficial depending on the concentration and the use. A UV meter can detect ultraviolet light on a wide range of sensitivities. UV meters can be purchased from many sources, including outdoor suppliers, scientific product companies, and many online merchants.
The sun is a large natural source of UV light, which can be dangerous for humans to be exposed to in some quantities. Sunblock and sunscreen are relatively effective defenses against UV light, but a UV meter can also be helpful to those spending time in the great outdoors. These simple meters allow users to know the level of UV rays and what type of protection might be necessary. For those who have skin extremely sensitive to burning, a UV meter can give a good indication of what level of sunscreen to use and how long it is safe to stay out in full sunlight.
Museums that hold historic pieces of art frequently use a UV monitor to measure potential damage done to priceless works. Just as ultraviolet rays burn skin, they can also damage parchment, canvas, paints, and other art-related materials over time. In the most famous museums, paintings and other pieces may be specifically placed in areas that protect them from most UV light, as determined by a UV meter. In some museums and collections, ultraviolet readings are taken on a regular basis to ensure that levels have not changed and are not reaching dangerous heights.
A UV meter is typically a small, handheld device that produces a digital reading based on data taken in through the sensors. Some may include guides that show where the UV level falls on a scale, or give recommendations based on readings about exposure time. Usually, a UV meter produced for home or outdoor use will only be able to sense UV light from the sun, rather than from artificial sources such as black lights.
Ultraviolet light has many uses, including as a sterilizer. Water and food is sometimes purified using ultraviolet germicidal irradiation, which uses focused UV light to destroy and sterilize microorganisms. It is also frequently used to sterilize medical tools and facilities, and even sometimes as an air purifier. To ensure that a UV sterilizer is working correctly, operators use a highly sensitive UV meter to detect whether or not the emitted rays are at acceptable level for sterilization.