We know that UV aging test chamber is divided into a variety of wavebands , including UV-A and UV-B ,and most people will ask what is the same for UVA and UVB ? If is it just different wavelengths , how about the functional aspects ?
I give you a brief description as following:
(English name: ultraviolet radiation b),It is based on the biological effect of the wavelength division of the purple line, UVB is outdoor UV, people in the outdoor activities directly into the skin , UVA and UVB, which are not absorbed by the ozone layer, are irradiated to the surface of the earth and brought to our skin hurt. UVB damage and protection has been thoroughly studied, it can make the skin in a short time sunburn,
Sunburn (for the average person is about 25 minutes), SPF is the UVB protection of the mark. UVB waveband, wavelength 275 ~ 320nm, also known as the red erythema effect of ultraviolet, medium penetration, its wave the longer part will be absorbed by the transparent glass, the sunlight contains most of the ultraviolet light by the ozone layer absorption, only less than 2% can reach the surface of the earth, in the summer and afternoon will be particularly strong, UVB UV On the human body with erythema effect, can promote the body of mineral metabolism and the formation of vitamin D, but long time or the amount of light will cause the skin to tan and cause redness and peeling
2. UVA wavebands
Wavelength of 320 ~ 400nm, also known as long-wave black spots effect of ultraviolet light, it has a strong penetration, you can wear through most of the transparent glass and plastic, sunlight contains long-wave ultraviolet, more than 98% can wear through the ozone layer and clouds reach the Earth's surface. UVA can reach the dermis of the skin, destroying elastic fibers and collagen fiber that will tan our skin.