Are black lights the same as UV lights? The answer is yes, but there's more to it than that. Black light is a type of UVA light, which is a type of UV light. However, UV light doesn't always appear black. It can come in many colors, including violet, blue, green, red, orange, and yellow.
Fluorescent black light tubes are usually made in the same way as regular fluorescent tubes, except that a phosphor that emits UVA light is used instead of visible white light. Incandescent lights don't emit much ultraviolet light because of their blackbody spectrum. Black lights can be used to tell real currency from counterfeit bills since many countries' legal banknotes have fluorescent symbols that only show up under a black light. In medicine, forensic science, and other scientific fields, this type of light source is known as a Wood lamp, named after Robert Williams Wood who invented Wood's original UV glass filters. Although other lamps emit ultraviolet light with visible light, black lights are essential when only UVA light is needed without visible light - especially to observe fluorescence, the colored glow that many substances emit when exposed to UV rays. Black lights were used by the U.
S., the United Kingdom, Japan and Germany during World War II to illuminate instrument panels. This offered a safer alternative to radio-painted instruments and an intensity that could be easily varied without visible lighting that would reveal the position of the aircraft. Although black lights produce UV light, their spectrum is mainly limited to the long-wave UVA region - the UV radiation closest in wavelength to visible light with a low frequency and relatively low energy. Black lights are used for decorative and artistic lighting purposes, diagnostic and therapeutic uses in medicine, detecting substances labeled with fluorescent dyes, rock hunting, scorpion hunting, detecting counterfeit bills, curing plastic resins, attracting insects and detecting refrigerant leaks affecting refrigerators and air conditioning systems. Incandescent bulbs are a cheaper alternative to fluorescent tubes but they're exceptionally inefficient at producing UV light since most of the light emitted by the filament is visible light that must be blocked. In conclusion, black light - also known as UV-A light, Wood lamp or ultraviolet light - is a lamp that emits long-wave ultraviolet (UV-A) light and very little visible light.
