| Ultra violet radiation (short waved UV) is one of many radiation forms, where they all belongs to the same category within electro-magnetic radiation: X-ray, light, radio and television, A.C. power.
The difference between the radiation types is decided by the wavelength. The shortest wavelengths are found within cosmic radiation and X-rays. Only a small area accounts for the optical radiation including ultra violet radiation, visible light and infrared radiation.
The UV spectrum is divided into three areas:
* UV-A, long wave, 315-400 nm
* UV-B, medium wave, 280-315 nm
* UV-C, short wave, <100-200 nm
The radiation from the UV-A group:
is also a part of the natural sunshine on the earths surface. This UV-A radiation causes different photochemical processes, it has a perceptible pigmenting - but in praxis no eythematic influence.
The radiations from the UV-B group:
shows both pigmenting and erythematic influence. They also form pre-vitamin D. This kin of radiation is mainly used within therapy.
Short waved UV-C radiation
has a strong germ fatal effect and also causes erythema and conjunctivitis. This kind of radiation can be made artificial, when a mercury low-pressure in UV-C lamps is discharged.
Radiation with wavelengths below 200 nm form ozone. |