UV is the abbreviation of Ultraviolet, Which is an ultraviolet light, so the ultraviolet tube called UV tube. Ultraviolet rays（UV）is no visible light，Is a electromagnetic radiation outside the visible purple light，wavelength is between 10~400nm.usually for different character, can be departed into the following：
a（Vacuum UV）， wavelength 10–200nm
e（Visible light），wavelength 400–760nm
The international general use is the long wave UV(UV-A）。
UV light spectrum
Anan electronic Co., Ltd is professional in manufacturing this type of tube, Fluorescent black light tubes are typically made in the same fashion as normal fluorescent tubes except that a phosphor that emits UVA light instead of visible white light is used. The type most commonly used for black lights, designated black light blue or “BLB” by the industry, has a dark blue filter coating on the tube, which filters out most visible light, so that fluorescence effects can be observed.
Two black light fluorescent tubes, showing use. The top is a F15T8/BLB 18 inch, 15 watt tube, used in a standard plug-in fluorescent fixture. The bottom is an F8T5/BLB 12 inch, 8 watt tube, used in a portable battery-powered black light sold as a pet urine detector.