Ultraviolet lamp release the short-wave ultraviolet radiation of 253.7nm to sterilize the bacteria and virus. In addition, some lamps also radiate the ultraviolet radiation of 185nm, which produces ozone in the air to sterilize. The intensity of ultraviolet radiation is the most basic factor affecting the disinfection effect. Use the meter to check the radiation after 3 to 6 month. If the ultraviolet radiation is more than 30% reduction. Must replace the old lamps. In order to ensure satisfactory disinfection effect, we mainly implement the following monitoring and management measures in use:
1.The radiation intensity of a lamp
The ultraviolet radiation intensity is the most basic factor affecting the disinfection effect. The new ultraviolet lamp should be greater than 100VW/cm2(at a distance of 1m) to qualify. The radiation intensity of the lamp in use should reach a minimum of 70VW/cm2, which can be used temporarily, but the irradiation time must be extended. If the intensity of the ultraviolet light source is lower than 40VW/cm2, then further extension of the irradiation time cannot play a satisfactory sterilization effect, that is, the use should be stopped. Do not think ultraviolet lamp tube as long as bright, there are sterilization.
2.Number of lamp tube installations
Indoor suspended ultraviolet disinfection lamp installation number (30W ultraviolet lamp, the radiation intensity at the vertical 1m higher than 70 micron W/cm2) is an average of not less than 1.5W per cubic meter, and requirements of uniform distribution, lifting height from the ground 1.8 ~ 2.2m, so that people's breathing belt in the effective irradiation range. Continuous irradiation is no less than 30min, and the radiation intensity of ultraviolet ray is inversely proportional to the radiation distance. The suspension is too high, which affects the sterilization effect. If the object surface disinfection, lamp tube distance from the irradiation surface should be 1m, sterilization is effective.
Environmental temperature has a certain impact on the intensity of ultraviolet radiation. Too high or too low temperature will reduce the radiation intensity. If the temperature drops to 4℃, the radiation intensity can drop by 65% ~ 80%, seriously affecting the sterilization effect. Generally, 20 ~ 40℃ at room temperature is the appropriate temperature for ultraviolet disinfection. Within this temperature range, the intensity of ultraviolet radiation is the largest and stable, which can achieve the ideal disinfection effect
High relative humidity and reduced penetration of ultraviolet radiation into cells. According to relevant literature, when the relative humidity is 55%-60%, ultraviolet radiation has the strongest killing rate of microorganisms; when the relative humidity is 60%-70%, the sensitivity of microorganisms to ultraviolet radiation decreases; when the relative humidity is 80% or more, it even has an activation effect on microorganisms, which can reduce the bactericidal force by 30%-40%. Just wet mop the ground and immediately undertake ultraviolet disinfection after wiping desktop, can make indoor humidity increases, affect disinfection effect. Accordingly, indoor when using ultraviolet disinfection should keep clean, dry.
5.Protection against UV radiation damage
Mainly to prevent ultraviolet radiation damage to the eyes, face exposed skin.Can not look directly at the tube to prevent conjunctivitis. Must not make ultraviolet ray illuminant irradiate to the person directly, in case the skin produces erythema. Ultraviolet radiation can release ozone, too much ozone can make people toxic, in human working environment, the concentration of ozone should not exceed 0.3mg/m3. Ultraviolet radiation should be carried out when the room is unoccupied. When conducting radiation intensity monitoring, special radiation intensity measuring tool ruler is used to conduct observation with the back to the light source. Ordinary glass or dark glasses can also be used as protective masks and protective glasses to protect the eyes and face skin.
6.Regular cleaning of lamp tube
Ultraviolet lamp surface dust and grease, will hinder the penetration of ultraviolet light, use should pay attention to the lamp wipe and cleaning, new lamp before use, can be wiped with 75% alcohol cotton ball. Generally wipe every 2 weeks during use. When discover lamp tube surface has dirt, smeary, answer to wipe at any time, keep lamp tube clean and transparent, lest affect ultraviolet ray to penetrate reach radiate intensity.
7.Strengthen the ultraviolet lamp radiation intensity monitoring
To the ultraviolet lamp in use 3 ~ 6 months then use ultraviolet radiation illuminance instrument to make intensity detection, discover intensity unqualified lamp tube wants to change in time. Calibration is done annually with the ultraviolet irradiance meter to maintain accuracy. When monitoring, it must be in accordance with the determination conditions in the "technical specifications for disinfection", the voltage is 220V or 110V, the temperature is above 20℃, the relative humidity is less than 60%, and the stable intensity after 5min of turning on the lamp is the radiation intensity of the ultraviolet sterilizing lamp. Can also be used to determine the intensity of ultraviolet radiation chemical indicator card, the indicator card from the lamp 1m irradiation for 1min, photosensitive paint from white into magenta, compared with the standard color block, it can be known the intensity of radiation tube.