Finsen Unit (FU)
Finsen Unit (FU) : A unit formerly used in medicine to measure the intensity of the ultraviolet light used in various medical treatments. Ultraviolet radiation of the standard wavelength 296.7 nanometers has intensity 1 Finsen unit if its energy density is 105?watts?per square meter. The unit honors the Danish physician Niels Finsen (1860-1904), who received the Nobel prize for medicine in 1903 for his research on the use of light in the treatment of various diseases