ultraviolet radiation
radiation for which the wavelengths are shorter than those for visible radiationNOTE 1 The range between 100 nm and 400 nm is commonly subdivided into:UV-A: 315 nm to 400 nm;UV-B: 280 nm to 315 nm;UV-C: 100 nm to 280 nm.NOTE 2 A precise border between "ultraviolet" and "visible" cannot be defined, because visual sensation at wavelengths shorter than 400 nm is noted for very bright sources.NOTE 3 In some applications the ultraviolet spectrum has also been divided into "far," "vacuum," and "near" ultraviolet; however, the borders necessarily vary with the application (e.g. in meteorology, optical design, photochemistry, thermal physics, etc.).Abbreviation: "UVR"