Terminology » Other Wireless » UVA vs UVB vs UVC: Understanding the Differences in UV Rays

UVA vs UVB vs UVC: Understanding the Differences in UV Rays

uv radiation uva uvb uvc electromagnetic radiation

This article compares UVA, UVB, and UVC ultraviolet ray types, focusing on their frequency, wavelength, and applications.

Introduction to Ultraviolet (UV) Rays

Ultraviolet (UV) rays are electromagnetic radiation with wavelengths ranging from 10 to 400 nm. These rays are shorter than visible light but longer than X-rays. UV rays constitute about 10% of the total electromagnetic radiation emitted by the Sun.

UV rays can also be produced artificially using electric arcs, lamps, and specialized lights. These rays are beneficial due to their ability to kill viruses, bacteria, and germs. They are also used in Line of Sight Communications for LiFi and Free Space Optics (FSO).

Furthermore, ultraviolet rays are used to disinfect drinking water, air, and tools, making UV light highly effective for sterilization and disinfection.

Despite the numerous benefits, UV rays also have drawbacks. They can be harmful to our eyes and skin, so direct exposure is not recommended. Additionally, UV light is most effective when it has a direct path; its effectiveness decreases when blocked by objects.

UV spectrum

UV Sub-bands

There are various sub-bands of UV rays, including UVA, UVB, UVC, near ultraviolet (NUV), middle UV, far UV, hydrogen Lyman-alpha, Extreme UV, and vacuum UV.

UV sub bands

Each of these sub-bands occupies different frequencies and wavelengths, as detailed below:

UVA

  • Full Form: Ultraviolet A
  • Frequency: 750 to 952.4 THz
  • Wavelength: 400 to 315 nm
  • Characteristics: Longest wavelength among UV rays
  • Pros: Less likely to cause tanning
  • Cons: Penetrates deep into the skin, causing skin aging and DNA damage

UVB

  • Full Form: Ultraviolet B
  • Frequency: 952.4 to 1071 THz
  • Wavelength: 315 to 280 nm
  • Cons: Affects the top layer of skin, causing tanning, redness, burns, and increasing the risk of skin cancer

UVC

  • Full Form: Ultraviolet C
  • Frequency: 1.071 to 3 PHz
  • Wavelength: 280 to 100 nm (Shortest wavelength; UVC light rays from the sun are absorbed by the atmospheric ozone layer)
  • UVC light at specific wavelengths is safe for use around humans. Special bulbs can emit appropriate amounts of UVC light, enough to effectively kill viruses.
  • Applications: Used to disinfect drinking water, medical tools, and air. It is also safe to use for disinfecting vegetables, fruits, mobile phones, surfaces, toys, utensils, and clothes.