An invisible band of radiation at the upper end of the visible light spectrum. With wavelengths from 10 to 400 nm, ultraviolet (UV) starts at the end of visible light and ends at the beginning of X-rays. The primary source of ultraviolet light is the sun, and most of the UV that reaches earth is in the lower-frequency, longer-wavelength Ultraviolet "A" region (see below).
Although ultraviolet (UV) light is widely known as a disinfectant, it is also used to erase EPROM chips. After several minutes of exposure to UV light, the chip can be programmed again (see EPROM).
Wavelength inUltraviolet Region Nanometers (nm)
Long Wave "A" UVA 315-400
Medium Wave "B" UVB 280-315
Short Wave "C" UVC 100-280
Near NUV 300-400
Middle MUV 200-300
Far FUV 122-200
Vacuum VUV 10-200
Extreme EUV 10-121
Deep DUV Below 300
Ultraviolet in the Spectrum
The ultraviolet band comes after visible light and ends at the beginning of X-rays.
Relating to electromagnetic radiation having frequencies higher than those of visible light but lower than those of x-rays, approximately 1015-1016 hertz. Some animals, such as bees, are capable of seeing ultraviolet radiation invisible to the human eye. See more at electromagnetic spectrum.
Ultraviolet light or the ultraviolet part of the spectrum. See Note at infrared.