Sterilization principle and application of ultraviolet ray

Ultraviolet (UV) has a wavelength range between X-ray (≤100 nm) and visible light (>Between 400 nm), in the range of about 100-400 nm.According to the interaction between ultraviolet ray and molecule,LED Ufo Grow Lights,

 it can be divided into four types, which have different physiological effects on substances.Vacuum UV (VUV) has a wavelength range of 100-200 nm.At low doses, it can also react immediately with oxygen and organic molecules, which can be harmful.Ultra-short ultraviolet (UVC) wavelengths range from 200 to 280 nm.UVC is completely absorbed by the atmosphere and no natural UVC rays reach the earth's surface.Ultraviolet light at this band has a bactericidal effect.The active "ingredient" in what is commonly referred to as "ultraviolet sterilization" is UVC[2], which can be obtained from artificial light sources (such as UVC leds or mercury lamps).The penetration capacity of UVC is weak, most of it will be absorbed by the cuticle and epidermal layer of the human skin, only a very small part of it will hit the dermis, and the ultraviolet light will only affect the dermis can cause the skin cell cancer, so it is generally considered that UVC on the human skin impact is not big (except for infants and UVC allergy to the population).However, because the eye does not have cuticle layer protection, UVC has harmful effect to the eye, so when using UVC disinfection room, the person should not enter it as far as possible, if must enter, must wear special protective glasses and protective clothing.Extreme ultraviolet (UVB) wavelengths range from 280 to 315 nm.This band of light can cause "sunburn" on the skin, which has been linked to cancer and photoageing, and the main purpose of applying sunscreen is to combat it.Near ultraviolet UVA wavelengths range from 315 to 400 nm.The short wavelength UVA (315-340 nm, UVA1) also has harmful effects on the skin due to its ability to produce reactive oxygen species.It is very penetrating, can penetrate most of the transparent glass and plastic, also can go to the skin dermis, destroy elastic fiber and collagen fiber, the skin tanned.