How do UV germicidal lamps work?
Ultraviolet germicidal lamps emit 253.7nm (254) ultraviolet light, and microbial cells in the absorption spectrum of nucleic acids coincide, thus destroying the microbial organism cells in the molecular structure of the DNA (deoxyribonucleic acid) or RNA (ribonucleic acid), resulting in the growth of cell death and regenerative cell death, to achieve the effect of bactericidal disinfection.
Why should the radiation dose be guaranteed rather than the biocide rate?
The effectiveness of UV sterilization is affected by the dose of UV irradiation and is not simply measured by the biocide rate. The bactericidal dose is the total amount of ultraviolet radiation received by a bacterium or microorganism and is calculated by the product of the intensity of the ultraviolet radiation and the duration of exposure. When using ultraviolet sterilization, it is necessary to ensure the radiation intensity and radiation time of the germicidal lamp to ensure the amount of bactericidal agent. Although the amount of bactericidal agent can be used to measure the effect of killing microorganisms, but can not directly reflect the bactericidal rate.
Different species of microorganisms have different sensitivities to UV light, and the required dose of UV radiation varies according to the type of microorganism. For example, 99.99 percent sterilization of E. coli requires a UV dose of ≥20,000 μW.s/cm2, while 99.99 percent sterilization of Mycobacterium spp. requires a UV dose of ≥100,000 μW.s/c2.
However, in reality, sterilization rates can be affected by a variety of reasons, such as the shape of the object being irradiated, the height of the irradiation, the duration of the irradiation, and the intensity of the light.
Although the larger the dose of ultraviolet radiation, the bactericidal rate will increase accordingly, there is no direct linear relationship between the dose of radiation and the bactericidal rate, excessive mention of light intensity or light time may lead to product quality deterioration or damage. Therefore, under the premise of keeping the sterilization effect, there is no need to over-pursuing the sterilization rate.