Who has not seen a lamp that emitted violet light and does not know what it is or what it is used for, because we will see that it is blacklight or Ultraviolet light, because it can be generated and its applications?
Blacklight or Ultraviolet light is the common name for lamps that emit near-ultraviolet electromagnetic radiation, with a tiny residual component of visible light.
What is ultraviolet light
Ultraviolet light is called those lamps that are capable of emitting ultraviolet electromagnetic radiation at close distances leaving a small residue of visible light.
Blacklight lamps are usually manufactured in the same way as conventional fluorescent lamps, except that they use a single phosphor, and instead of the transparent outer glass they use a dark glass known as Wood’s glass, which blocks most of the visible light with a wavelength above 400 nanometers.
How Ultraviolet Light works
Blacklight or Ultraviolet, works in the same way as a common fluorescent lamp, with the difference is that the blacklight lamps use only one phosphor and that to cover the lamp does not use a transparent glass but a darker crystal called glass of Wood.
The glass of Wood has the function of blocking the electromagnetic waves that have a length greater than 400 nanometers, that is why these lamps emit ultraviolet radiation with a wavelength of 350nm.
Blacklight lamps can be found in many places and used for different purposes, with them you can see many objects glow in the dark, while the lamp itself only emits a faint purple light.
These lamps work in a similar way to fluorescent lamps, in these the light is produced by flowing electricity through inert gas and a small amount of mercury.
This produces light in the ultraviolet spectrum, invisible to the human eye, and to produce light a type of substances called phosphors that cover the interior of the lamp is used.
By absorbing ultraviolet light these phosphors emit visible light, as the human eye can not detect this ultraviolet light is called black light, and blacklight lamps work with the same principle.
The phosphors that cover its interior absorb the ultraviolet light of the waves called UV-B and UV-C, which are harmful, by absorbing them, instead of emitting white light they emit UV-A, which is more benign.
In the case of black light bulbs, filters are used to absorb the light of the incandescent filament, but they allow UV-A light to pass, while at the same time this type of ultraviolet light also passes a little purple light.
Now, there are a lot of materials that work like phosphors, when they receive UV-A ultraviolet light, they absorb it and emit visible light, just like the phosphors of ordinary lamps do.
Uses of Ultraviolet Light
- To obtain dim lighting.
- To highlight some colors on others in dark environments.
- To easily see if a bill is false or true.
- In criminology, it serves to find fingerprints on a surface.
- In bars or clubs to create a shine in fluorescent or white clothing.
- To highlight engravings that can only be viewed under black light.
- For decoration (to a lesser extent).
Ultraviolet Light Lamps
Ultraviolet light lamps are manufactured in the same way as conventional fluorescent lamps, as mentioned above only some components vary.
Conventional fluorescent lamps are manufactured with various types of phosphors, while those of black light only use a single phosphor, on the other hand, a transparent glass covers conventional lamps.
These allow the passage of any wavelength, while the black light lamps are covered by Wood’s crystal, which does not allow the passage of electromagnetic waves with a longer wavelength than 400 nm.
The black light lamp can be used in any lighting system, from something manual, home to industrial, can be turned on manually or even with a photoresist, which does not make much sense since it does not illuminate too much, but it is an option at the end and finally.