UV is divided into: near ultraviolet UVA, far ultraviolet UVB and ultrashort ultraviolet UVC according to the wavelength. The shorter the wavelength of ultraviolet rays, the greater the harm to human skin. Short-wave ultraviolet rays can penetrate the dermis, while medium waves can enter the dermis.
shortwave ultraviolet: abbreviated as uvc. is the ultraviolet light of the wavelength 200NM-280NM. Short-wave ultraviolet light is absorbed by the ozone layer as it passes through the stratosphere of the earth's surface. Can not reach the surface of the earth, the human body has an important role. Therefore, sufficient attention should be paid to short-wave ultraviolet rays.
medium wave uv: short for uvb. is UV at the wavelength of 280NM-320NM. Medium wave ultraviolet has certain physiological effect on human skin. A large portion of such UV rays are absorbed by the skin epidermis and cannot penetrate into the skin. However, because of its high level of energy, the skin can produce strong light damage, the exposed site of dermal vasodilation, skin can appear redness, blisters and other symptoms. Long-term exposure to the skin will appear erythema, inflammation, skin aging, severe can cause skin cancer. Medium-wave ultraviolet radiation, also known as ultraviolet sunburn (red) section, should be the focus of prevention of ultraviolet radiation band.
long wave uv: short for uva. is UV at wavelength 320NM-400NM. Long-wave ultraviolet rays are far more penetrating to clothing and human skin than medium-wave ultraviolet rays, reaching the depths of the dermis and acting on melanin in the epidermis, causing skin melanin to cool, blackening and protecting against ultraviolet rays. So long-wave ultraviolet light is also called "tanning section ". Although long-wave ultraviolet rays do not cause acute inflammation of the skin, but the effect on the skin is slow, can accumulate for a long time, is one of the causes of skin aging and serious damage.
The main source of uv light sterilizer in nature is the sun, which absorbs ozone in the atmosphere when sunlight penetrates the atmosphere at a wavelength shorter than 290 nm. Artificial ultraviolet light sources have a variety of gas arcs (e.g. low-pressure mercury arcs, high-pressure mercury arcs), ultraviolet light has a chemical effect on photographic negatives, strong fluorescence, fluorescent lights, various fluorescent lamps and agricultural black lamps used to trap insects are used to stimulate fluorescent substances to glow. Ultraviolet rays can also be anti-counterfeiting, ultraviolet rays have physiological effects, can sterilize, disinfect, treat skin diseases and cartilage diseases. UV has strong particle properties and can produce photoelectric effects on various metals Should.