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Use and detection method of ultraviolet germicidal lamp

2022.09.30 Edit: Juguang Read:7006

Ultraviolet germicidal lamps mainly rely on 253.7 nm short wave ultraviolet radiation to sterilize and disinfect. In addition, some lamps also radiate 185 nm ultraviolet radiation, which will produce ozone in the air and have the function of sterilization. The ultraviolet radiation intensity is the most basic factor affecting the disinfection effect. The ultraviolet lamp in use should be tested with the ultraviolet radiation illuminometer every 3 to 6 months. If the lamp tube intensity is found unqualified, it should be replaced in time. In order to ensure satisfactory disinfection effect, we mainly implemented the following monitoring and management measures in use:

1. Radiation intensity of lamp

The ultraviolet radiation intensity is the most basic factor affecting the disinfection effect. According to the requirements of the Disinfection Technical Specifications, the radiation intensity of the new ultraviolet lamp should be greater than 100VW/cm2 (1m away), which is qualified. The minimum radiation intensity of the lamp in use should be 70VW/cm2, which can be used temporarily, but the exposure time must be extended. According to the formula that the ultraviolet radiation dose is equal to the radiation intensity times the exposure time, the extended exposure time required for different intensities can be calculated. It can also be seen that the same sterilization effect can be obtained for high intensity short time or low intensity long time. If the intensity of the ultraviolet light source is lower than 40VW/cm2, the longer exposure time can not play a satisfactory bactericidal role, that is, the use should be stopped. Don't think that as long as the ultraviolet lamp is on, it will have bactericidal effect.

2. Number of tubes installed

According to the provisions of Volume 2 (Hospital Disinfection Specifications) of the Third Edition of the Technical Specifications for Disinfection issued by the Ministry of Health, the number of indoor suspended ultraviolet disinfection lamps (30W ultraviolet lamps, with radiation intensity higher than 70 at 1m vertically μ W/cm2) is not less than 1.5W per cubic meter on average, and it is required to be evenly distributed, and the lifting height is 1.8~2.2m from the ground, so that the respiratory belt of people is in the effective exposure range. Continuous irradiation shall not be less than 30min. The radiation intensity of ultraviolet ray is inversely proportional to the radiation distance, and the suspension is too high, affecting the sterilization effect. If the surface of the object is disinfected, the distance between the lamp tube and the illuminating surface should be 1 m, so that the sterilization is effective.

3. Ambient temperature

The ambient temperature has a certain impact on the ultraviolet radiation intensity. Too high or too low temperature will reduce the radiation intensity. If the temperature drops to 4 ℃, the radiation intensity will decrease by 65%~80%, seriously affecting the sterilization effect. Generally, room temperature of 20~40 ℃ is the appropriate temperature for ultraviolet disinfection. Within this temperature range, the intensity of ultraviolet radiation is maximum and stable, which can achieve ideal disinfection effect

4. Relative humidity

The relative humidity is high, and the penetration of ultraviolet radiation into cells is reduced. According to relevant literature, when the relative humidity is 55%~60%, the killing rate of ultraviolet rays on microorganisms is the strongest. When the relative humidity is above 60%~70%, the sensitivity of microorganisms to ultraviolet rays is reduced. When the relative humidity is above 80%, even it can activate microorganisms, which can reduce the bactericidal power by 30%~40%. Ultraviolet disinfection will increase the indoor humidity and affect the disinfection effect when the floor is wet and the desktop is wiped immediately. Therefore, keep the room clean and dry when using ultraviolet disinfection

5. Prevent ultraviolet radiation damage

It mainly prevents ultraviolet radiation damage to the eyes and exposed skin on the face. Do not look directly at the lamp to prevent conjunctivitis. Do not let the ultraviolet light source directly irradiate people to prevent skin erythema. Ultraviolet rays can release ozone, and excessive ozone can cause poisoning. In a manned working environment, the concentration of ozone shall not exceed 0.3mg/m3. Ultraviolet radiation shall be conducted when the room is unoccupied. During radiation intensity monitoring, a special radiation intensity detection tool ruler is used to observe with the back to the light source, or ordinary glass or sunglasses can be used as a protective mask to protect eyes and face skin.

6. Regular cleaning of lamp tubes

The dust and oil dirt on the surface of the ultraviolet lamp tube will hinder the penetration of the ultraviolet ray. Pay attention to the wiping and cleaning of the lamp tube during use. Before using a new lamp tube, use a 75% alcohol cotton ball to wipe it. During use, it is generally wiped every 2 weeks. When dust and oil stain are found on the surface of the lamp tube, it shall be wiped at any time to keep the lamp tube clean and transparent, so as not to affect the penetration and radiation intensity of ultraviolet ray.

7. Strengthening the Monitoring of Ultraviolet Lamp Radiation Intensity

The ultraviolet lamp in use shall be tested for intensity with the ultraviolet radiation illuminometer for 3-6 months, and the lamp tube with unqualified intensity shall be replaced in time. The ultraviolet radiation illuminometer shall be calibrated once a year to maintain accuracy. During monitoring, the voltage shall be 220V, the temperature shall be above 20 ℃, and the relative humidity shall be less than 60% according to the measurement conditions in the Disinfection Technical Specifications. The radiation intensity of the ultraviolet disinfection lamp shall be the stable intensity after the lamp is turned on for 5min. The ultraviolet radiation intensity can also be measured with a chemical indicator card. When the indicator card is irradiated at a distance of 1m from the lamp tube for 1min, the photosensitive coating changes from white to purple red. Compared with the standard color block, the radiation intensity of the lamp tube can be known.

Ultraviolet germicidal lamps are widely used in water treatment, central air conditioners, refrigerators, air purifiers, microwave ovens, disinfection cabinets, food factories, hotels, schools, hospitals, theaters and other places, with a complete range of products at low prices, including straight tube type, H-type, special-shaped, power 4W, 5W, 6W, 7W, 8W, 9W, 10W, 11W, 15W, 16W, 18W, 25W, 30W, 36W, 40W, 55W, 64W, 75W, 115W

Jiangsu Juguang Optoelectronic Technology Co., Ltd. has developed and produced a series of ultraviolet air disinfectors, plasma air disinfectors, mobile disinfectors, bed unit disinfectors, lamp racks and other products based on the core of ultraviolet disinfection lamps. With strong functions, multiple varieties and stable quality, they are used in hospitals, families, schools, government institutions and public places. The annual production and sales of air disinfectors reach more than 10000 sets. The company's products are in variety, output The quality has been continuously improved in many aspects, and is well received by users at home and abroad.