Ultraviolet (UV) light is a type of electromagnetic radiation on the electromagnetic spectrum. The frequency of UV light is higher than that of visible light. This means it has more energy, which makes its wavelength shorter. This increased energy causes chemical effects in many objects — such as skin, plastics, and even some clothing dyes. One major difference between UV and visible light is its wavelength; UV has a smaller wavelength than visible light. The electromagnetic spectrum is divided into different “bands” depending on wavelength - ultraviolet light is the shortest, while infrared light is the longest. The term “visible light” refers to the part of the spectrum that the human eye can see. A majority of the UV rays that humans come in contact with the sun. However, other UV light sources also exist. Black lights, mercury lamps, and tanning lights all emit at levels of UV radiation. (image will be updated soon) Wavelength and Frequency of UV RaysElectromagnetic waves work differently. All waves of the same type of frequency travel at the same speed. But their wavelength and frequency differ, depending on the type of wave. The frequency of a wave is measured in Hertz; its unit is Hz. UV light wavelengths are measured in nanometres, with one nanometre equal to one billionth of a metre. Ultraviolet rays are shorter wavelengths than visible light, which is why we cannot see them when seen naked-eye. Ultraviolet rays are in the wavelength range from 10 to 400 nanometers (nm). They come in the frequency range of 800 terahertz (THz) to 30 petahertz (PHz). Ultraviolet radiation is usually divided into four regions.
Types of UV LightUV Rays are separated into three groups: UV-A, UV-B, and UV-C. Each group has a distinct characteristic. Ultraviolet A (UVA) Ultraviolet B (UVB): Ultraviolet C (UVC) 1. 98.7% of the UV light reaching Earth is UVA. It is affected by the ozone. 2. Fading of paints and dyes. 3. UVA causes early ageing of the skin. 4. UVA causes skin cancer called melanoma. 1. 1.3% of the UV reaches the earth’s surface and is highly affected by ozone. 2. For the production of vitamin D, 270-300 nm wavelengths are responsible. 1. UVC rays do not reach the earth’s surface as most of them are absorbed by the atmospheric nitrogen, oxygen, and ozone, and the rest are scattered. 2. UVC causes lesions on the skin. Use of Ultraviolet RaysUltraviolet light has many uses, including treating skin diseases like lupus and vitiligo, but photography is one of its most common uses. The same technology that produces blacklight posters, fluorescence art, sunless tanning solutions, and teeth whitening products also provides us with protection from pests like bed bugs. Here are some of UV light uses in detail:
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