In electronics stores I saw ultraviolet lamps that have transparent glass and black lights that have violet glass. Are not they the same thing, emitting both ultraviolet radiation?
In fact, both types of lamps emit ultraviolet radiation, but there is a difference in intensity and wavelength. The so-called black light bulbs, or simply black light, emit ultraviolet radiation of small intensity in the part of the spectrum near violet, being used in lanterns to verify fluorescence and also with decorative effects and dances and windows. The weak radiation of these lamps is not harmful to people and therefore there are no restrictions on their use. On the other hand transparent glass ultraviolet lamps are lamps that emit ultraviolet radiation of high intensity in a broader range of the spectrum being used in several types of applications like bactericide, to erase EPROM memories, to record in photosensitive plates, etc. The radiation from these lamps is dangerous to our eyes and should therefore always be used in places that are not covered, so that their light reaches our sight.
