Ultraviolet disinfection lamp can destroy the molecular structure of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) in microbial cells by ultraviolet light of appropriate wavelength. The energy of ultraviolet photons is absorbed by the base pair in DNA. The effect of ultraviolet radiation on nucleic acid can lead to the breaking of bonds and chains, cross-linking between strands and the formation of photochemical products, etc., thus changing the biological activity of DNA. It results in the death of growing cells and / or the death of regenerated cells or the inability to reproduce, so as to achieve the effect of sterilization and disinfection.
The experimental results show that the effective wavelength range of ultraviolet sterilization can be divided into four different bands,: UVA (400~315nm), UVB (315 ~ 280nm), UVC (280~200nm and vacuum ultraviolet (200 ~ 100nm). Only UVA and UVB can reach the earth's surface through ozone protection and clouds. In terms of bactericidal rate, UVC is within the range of microbial absorption peak and can kill viruses and bacteria by destroying the DNA structure of microorganisms in ls, while UVA and UVB are in the range of microbial absorption peak. In addition, the sterilization rate is very slow, it often takes several hours to play a bactericidal effect, in the actual project for a few seconds of hydraulic retention (irradiation) time, this part is actually an invalid ultraviolet part. The bactericidal effect is determined by the irradiation dose accepted by microorganisms. At the same time, it is also subject to the output energy of ultraviolet light, which is related to the type of lamp, light intensity and use time. As the lamp ages, it will lose 30% less than 50% of the intensity. Ultraviolet irradiation dose refers to the amount of ultraviolet radiation at a specific wavelength when reaching a certain bacterial inactivation rate: irradiation dose (J/m2) = irradiation time (s) XUVC intensity (W/m2) The higher the irradiation dose, the higher the disinfection efficiency. Because of the equipment size requirements, the general irradiation time is only a few seconds, so the UVC output intensity of the lamp becomes a measure of UV.The most important parameters of the performance of optical disinfection equipment.