| UV Light & UV Lamps Info |
| The Ultraviolet Spectrum Ultraviolet refers to all electromagnetic radiation with wavelengths in the range of 10 to 400 nanometers (nM), or frequencies from 7.5E14 to 3E16 Hz. The UVA range is wavelengths from 315 to 400 nM. Wavelengths from about 345 to 400 nM are used for "blacklight" effects (causing many fluorescent objects to glow) and are usually very slightly visible if isolated from more visible wavelengths. Shorter UVA wavelengths from 315 to 345 nM are used for suntanning. UVB refers to wavelengths from 280 to 315 nM. These wavelengths are more hazardous than UVA wavelengths, and are largely responsible for sunburn.. The ozone layer partially blocks these wavelengths. UVC refers to shorter UV wavelengths, usually 200 to 280 nM. Even shorter wavelengths from 10 to 200nM are usually considered separately as "vacuum ultraviolet " since they are absorbed by air, although these wavelengths are also considered a shorter range of UVC. Wavelengths in the UVC range, especially from the low 200's to about 275 nM, are especially damaging to exposed cells. Such shortwave UV is often used for germ- killing purposes. Fluorescent Blacklights There are fluorescent tubes that emit UV. The phosphor coating on the inner surface of the tube absorbs the UVC emitted by the low pressure mercury arc, and emits longer UV wavelengths.There are at least six different UV-emitting phosphors used in fluorescent lamps. There are UV fluorescent lamps with glass not dyed to block visible light. This includes the BLB lamps and the similar 250 BL. These are often used to attract and zap pesky insects. There are at least two other fluorescent UV lamps producing long UV wavelengths close to visible violet. These are less common and sometimes used in some special photographic and printing processes. Info written by Don Klipstein (Thanks, Don) of www.misty.com |
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| Handheld UV Spotlight (picture courtesy of Novalite) |
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