Until relatively recently, no one had heard of LEDs capable of emitting light in such spectra as infrared or ultraviolet. And now many areas of production can no longer imagine work without such sources. Medicine, industry, forensics and even banking - ultraviolet LEDs quickly spread to all industries where they became completely indispensable due to their radiation properties, durability and low energy consumption. In today's article, we are talking about such elements, their features and properties.
General information about ultraviolet emitters
This LED owes its appearance to the engineer of Nichia Corporation, Shuji Nakamura. In 93 of the last century, he was able to create an element with a blue glow. For this invention, the engineer even received the Nobel Prize. The fact that UV LEDs are in demand inmany areas, no doubt. However, they have a rather significant drawback over conventional ones - low efficiency. The reason lies in the fact that half of the energy spent on its work is converted into heat. That is why high-quality radiators are needed for such emitters.
Some parameters of various LEDs
The characteristics of UV LEDs are similar to simple white or colored elements, but it is worth noting that the concept of color temperature is irrelevant for him. The rating of the operating current, as well as the indicator of forward voltage or luminous flux, in comparison with conventional LEDs, is similar. But there is one important difference that makes it valuable for a variety of uses. 100-400 nm of an ultraviolet LED is the indicator by which the emitter is selected for a particular application. It is on the areas of use that it is now worth dwelling in more detail.
Where LEDs of a similar spectrum are used
Here are 5 main areas that are in greatest need for such emitters.
- Medicine. Here such rays can be used for disinfection. In dentistry, they contribute to the rapid hardening of fillings, and in cosmetology - disinfection of hands after manicure and drying of gel polishes.
- Industry. Accelerate the drying process of adhesives that react to such radiation.
- Banking - indicationauthenticity of banknotes, detection of fakes.
- Forensics - detection of invisible biological traces, washed blood, etc.
- Agriculture. Lamps with UV LEDs are installed in greenhouses. Their radiation contributes to the growth of vegetables, the destruction of pests, the production of antioxidants.
Some features of real ultraviolet
There are many myths around such emitters. For example, that from such lighting you can quickly go blind. Many believe that if the LED has a characteristic color, then this is ultraviolet. In fact, they are wrong in both the first and second cases.
UV LEDs do not have any harmful effects on the human body - this fact has already been proven. Of course, if a direct stream of such radiation hits the eyes, pain and tearing will appear, but hardly anyone will do this on purpose. As for color, it has nothing to do with ultraviolet, which is completely invisible to the human eye. Ultraviolet emitters can glow blue or white, or it may not be noticeable at all. But it is worth returning to he alth. Scientists have proven an interesting fact about the blue glow, which needs to be discussed in more detail.
Which color is most harmful to the human body
As it turned out, the blue glow greatly affects the productionMelatonin is a hormone responsible for the phases of sleep and wakefulness. With the constant exposure of such an ultraviolet LED to the body, some changes occur. Melatonin starts to be produced more slowly. What does this mean for a person? First, the usual regimen is violated, sleep becomes restless. Further, significant hormonal changes occur, due to such violations, a person becomes irritable, falls into depression. The result (in theory) may be the complete destruction of the nervous system with the final cessation of the body's production of melatonin.
However, only initial changes have been proven, which are due to restlessness of sleep. The rest is theoretical speculation, which has no official justification, and therefore should be treated accordingly. Of course, such a theory immediately found many followers who began to “shout” at every corner about the mortal danger of such radiation. However, at the same time, for some reason, they forget how much more harmful to the body was the predecessor of ultraviolet spectrum LEDs - a quartz lamp. Even a fluorescent tube does more harm to the body!
In any case, do not sow panic until the harmful effects of LED ultraviolet radiation on the body of people or animals are reasonably proven.
Which compare LED to ultraviolet radiation
Many people ask which of these elements are closer in terms of technicalcharacteristics to those that are considered today. The most similar can be called white, having the following parameters:
- LED voltage range - 3-4V;
- The indicator of operating currents is about 20 mA for weak emitters and 350-700 mA for high power elements.
It turns out that one power supply is suitable for both. Such information is very important, because if a chain of white LEDs is assembled in the house, it can be replaced with ultraviolet without purchasing an additional adapter. If the emitters have a different color, you will have to spend money.
Summing up
The fact that ultraviolet LEDs have become a breakthrough in the field of such emitters is beyond doubt. It is surprising how extensive their scope is in the modern world, although until relatively recently there was not even a talk about this. Perhaps something new will appear in the future, but today the best in this area has not been invented.
