Ultraviolet, all the explanations

Know how ultraviolet light works
to understand the process of
sterilization and disinfection.

What are UVC rays?

Rayon UVC

The origin of the word Ultraviolet

Ultra means beyond something.

Violet meanwhile is the last color visible to the naked eye.

What is an Ultraviolet ray?

Ultraviolet rays were discovered in 1801 by German physicist Johann Wilhelm Ritter.

It was only in 1878 that the sterilizing and germicidal action of UVC was discovered. Many viruses and other bacteria spread through the air: UVC light is a very effective way to stop their spread.

These are electromagnetic waves that are invisible to the naked eye. They are also known as “black light” . UV have more or less long electromagnetic wavelengths but always lower than that of light , this is what makes them invisible to the naked eye.

These UV rays are measured in electromagnetic wavelengths expressed in nanometer “nm”. They have wavelengths between 400 to 10 nanometers depending on the category.

The longer the UV wavelength, the closer it approaches that of light . This means that the longer the UV wavelength, the less energy it has.

Conversely, the shorter the wavelength, the more harmful and destructive energy it contains.

Rayon uv

The different categories of UV according to their wavelengths:

  • UV-A between 315 and 400 nm
    95% of these solar UV rays reach the surface of the earth
    We use this black light to make certain substances appear, such as on banknotes , it is also used by the scientific police.
  • UV-B between 280 and 315 nm
    Solar UV-B rays are largely filtered by the atmosphere.
    These waves contribute to tanning and allow the body to synthesize vitamin D
    They are also responsible for tanning and sunburn.
  • UV-C between 100-280 nm
    Solar UV-C are completely filtered by the ozone layer , they contain much more energy than the two previous ones.
    The particularity of these short electromagnetic waves is that they destroy the DNA and RNA of all microorganisms. The optimum wavelength for sterilization is 265 nm .
  • EUV between 10 to 100 nm
    These EUVs are said to be extreme and are used in the manufacturing industry for the production of electronic chips .

Some UV applications:

  • UV used for polymer drying (example: nail polish or glue)
  • UV can be used in biochemistry for effects with fluorescent dye
  • UV used in shows for light shows
  • UV used by the scientific police to reveal organic substances .
  • UVC used for sterilization
  • And there are still many other applications…
Utilisation UVC

What are UVs?

These are electromagnetic waves that are invisible to the naked eye, they are also known as “black light”. UV rays have more or less long electromagnetic wavelengths but are always lower than that of light, which is what makes them invisible to the naked eye.

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