Factors affecting the effect of ultraviolet germicidal lamps
Ultraviolet dose = radiation illuminance x exposure time
Ultraviolet sterilization is jointly determined by two parameters: sterilization dose: ultraviolet radiation illuminance (μW/cm²) x exposure time (seconds); bacteria type and environmental conditions.
Most UV germicidal lamps currently on the market use low-pressure mercury lamp technology. According to my country’s current national standard "GB19258-2012 Ultraviolet Germicidal Lamps", this standard is applicable to double-ended, single-ended or self-ballasted lamps with or without ozone and ultraviolet radiation peak wavelength of 253.7nm produced by using quartz glass. . From this we can see that the actual UV sterilization wavelength of the low-pressure mercury lamp is 253.7nm, which is the most effective ultraviolet sterilization wavelength for artificial ultraviolet light sources currently on the market, and it is also the internationally popular standard sterilization band for ultraviolet sterilization lamps. According to the requirements of the national standard "GB19258-2012 ultraviolet germicidal lamp" for germicidal lamps: the ultraviolet radiation illuminance is in μW/cm² as the unit, which is used to express the radiation intensity of the ultraviolet germicidal lamp. The test distance is required to be 1000mm±1mm, which is the distance from the surface of the lamp tube to the surface of the measuring instrument. The dose of ultraviolet light directly affects the sterilizing effect of the ultraviolet germicidal lamp, and the sterilizing power of ultraviolet light is also related to the specific bacteria type, temperature, humidity and exposure time.
In general, the bactericidal power of ultraviolet rays for each type of bacteria depends on the bactericidal dose, that is, the illuminance of ultraviolet radiation (μW/cm²) x exposure time (seconds). Generally, if the irradiation time is doubled, the same sterilization effect can be obtained even if the ultraviolet illuminance is halved. The sterilization effect is affected by the irradiation time, distance and the irradiance of the ultraviolet germicidal lamp. In the case of the same irradiation time and distance, the greater the irradiance, the better the sterilization effect.