UV sterilization

Ultraviolet rays are divided into three types according to wavelength: long-wave ultraviolet, medium-wave ultraviolet and short-wave ultraviolet. The specific ultraviolet intensity can be detected with an ultraviolet radiation meter.

　　 Long-wave ultraviolet, also known as UVA, with a wavelength of 315-400nm. The ultraviolet rays in the sun are almost all UVA, most of the UVA can reach the surface of the earth, and it has the effect of destroying elastic fibers and collagen fibers on people's skin, which is to tan people's skin. But there is no bactericidal effect.

　　 Medium-wave ultraviolet, also known as UVB, wavelength 280-315nm. A small part of sunlight is UVB, because most of the UVB in sunlight is absorbed by the ozone layer, and less than 2% can reach the surface of the earth. UVB ultraviolet rays have erythema effects on the human body, which can cause skin swelling and molting. There is also no bactericidal effect.

　　 Short-wave ultraviolet, also known as UVC, with a wavelength of 200-280nm, is also known as short-wave sterilizing ultraviolet. Ultraviolet rays in sunlight do not have the UVC band. This wavelength of ultraviolet rays is extremely harmful to the human body. The wavelength is short and is completely absorbed by the ozone layer. UVC has a strong sterilization ability, and the ultraviolet germicidal lamp emits UVC.

　　 Not all ultraviolet rays have a bactericidal effect, only certain wavelengths have this function. The UV light meter is used to detect the actual radiation intensity of the ultraviolet germicidal lamp to help people determine whether it meets the requirements for disinfection and sterilization.

Regarding the radiation intensity of the germicidal lamp, in accordance with the requirements of the "Disinfection Technical Specification", the radiation intensity of the new lamp should be more than 100μW/cm² (at a distance of 1m) to be monitored by the UV light meter LS126C, which is qualified, and it is in use The low radiation intensity of the lamp should reach 70μW/cm² and it can be used temporarily, but the irradiation time should be extended. Because high-strength short-time or low-strength long time can achieve the same sterilization effect. If the radiation intensity of the lamp tube is lower than 40μW/cm² by using an ultraviolet irradiance meter, it will not have a satisfactory sterilization effect if the irradiation time is extended, and the use should be stopped.