Some Problems Needing Attention in Using Ultraviolet Germicidal Lamp
Ultraviolet germicidal lamp has strong germicidal efficacy. It is suitable for sterilization in health, medical, biological research, pharmaceutical industry and food industry, as well as photochemical reaction, food storage and room air disinfection. The emission spectrum of ultraviolet germicidal lamp mainly includes 254nm and 185nm. 254 nm ultraviolet light kills bacteria by irradiating microbial DNA. 185 nm ultraviolet light can change O2 in the air into O3 (ozone). Ozone has strong oxidation, which can effectively kill bacteria. The dispersion of ozone can just make up for the shortcomings of ultraviolet light that only travels in straight lines and disinfects with dead corners. So what problems should be paid attention to when using ultraviolet germicidal lamp? Now let's introduce the experts of Jiangsu Juguang Optoelectronic Technology:
1、 Irradiation intensity of ultraviolet sterilization lamp:
In China, the number of ultraviolet lamps with a distance of 70 uw/cm2 (1m) accounts for almost 50_ 80%, according to the requirements of the disinfection technical specifications of the Ministry of Health, the qualification rate is less than 50%. Some units use ultraviolet germicidal lamps whose radiation intensity is less than 70uw/cm2 (1m away). Some even less than 40uw/cm2 are still in use. It should be known that each microorganism has its own specific threshold of ultraviolet killing dose. The sterilization dose (K) is the product of the irradiation intensity (I) and the irradiation time (t), K=It. It can be seen from the formula that high intensity short time or low intensity long time irradiation can achieve the same sterilization effect However, if the UV intensity is less than 40uw/cm2, the further extension of the irradiation time cannot achieve satisfactory sterilization effect. There is a problem of microbial damage repair, which is mainly intended to increase the irradiation intensity
2、 The space scope of ultraviolet radiation:
Many UV germicidal lamp users ignore the effective space range of UV radiation and only consider and calculate the plane area of radiation In addition to the area factor, the height of each disinfected space varies from high to low, and the total space range varies from large to small. For the use of sterilization lamps, the total space cube should be calculated and the corresponding ultraviolet sterilization lamp should be used. The effective sterilization space range of a 30w sterilization lamp should be less than 30m3. Generally speaking, the sterilization lamp power of each cubic meter of space should be more than 1-1.5w, and attention should be paid in use.
3、 Irradiation distance of lamp tube suspension:
When using ultraviolet germicidal lamp, attention should be paid to the irradiation distance between the sterilized object and the germicidal lamp, that is, the hanging height of the lamp tube should be less than 2.5 meters, and some units using the lamp tube with a hanging height of more than 2.5 meters, or even more than 3 or 4 meters The irradiation intensity of ultraviolet ray is almost inversely proportional to the irradiation distance. If the suspension is too high, it will inevitably affect the sterilization effect.
4、 Deterioration of ultraviolet radiation intensity:
The irradiation intensity of the ultraviolet germicidal lamp will gradually decline with the extension of the use time According to multiple measurements, the decay rate of quartz lamp tube is less than 20% after 1000 hours of use, while that of high boron lamp tube is more than 30% after 200 hours of use. In addition, the radiation intensity of high boron lamp tube itself is less than 70uw/cm2, so quartz ultraviolet disinfection lamp tube should be used. Quartz ultraviolet germicidal lamp is characterized by high radiation intensity and slow decay The raw material of quartz lamp is natural crystal stone, with the purple transmission rate of more than 80%, while the purple transmission rate of high boron glass is less than 50%, with low purple transmission rate and low radiation intensity.
5、 In application, attention shall also be paid to the wiping and cleaning of lamp tubes:
When using a new lamp, first wipe the lamp tube with 75% alcohol gauze to remove the pollution of dust and oil stains on the lamp tube In the process of use, wipe regularly and do a good job of cleaning the lamp tube to avoid affecting the violet transmission rate and radiation intensity.
6、 When using ultraviolet germicidal lamp, attention should also be paid to prevent ultraviolet radiation damage:
It is mainly used to prevent ultraviolet radiation damage to eyes and face, especially to eye conjunctiva. After the face is damaged by radiation, eyes become red, swollen, teary, and tingling, which is more serious than electric eye damage It will take three or four days to recover. (In case the conjunctiva is damaged by ultraviolet radiation, human milk can be used for eye drops once every half an hour, and three to four times is better) Prevention method: Focus on avoiding facing the light source. When monitoring and rechecking the radiation intensity of the ultraviolet germicidal lamp, use the specially made radiation intensity or sunglasses as the protective mask and goggles, but never use the protective equipment made of quartz glass as the raw material. Since the ultraviolet transmission rate of quartz glass to the ultraviolet line is more than 80%, while ordinary glass can hardly penetrate the ultraviolet light, it can effectively prevent the ultraviolet radiation damage.
7、 Strengthen the monitoring of the irradiation intensity of the ultraviolet germicidal lamp:
It is a very important work in the application of ultraviolet disinfection All users of ultraviolet germicidal lamps shall conduct intensity testing once every three to six months with radiation meter. The health and epidemic prevention monitoring department shall monitor the intensity of the units using ultraviolet germicidal lamps every half a year (twice a year). If it is found that the intensity is insufficient, the lamps shall be replaced in time The ultraviolet radiation meter shall be calibrated once a year to ensure its accurate performance. When monitoring the radiation intensity, it must be monitored according to the measurement conditions in the technical specifications of the Ministry of Health, voltage 220V, temperature 20'C, RH<60%, and the stable intensity five minutes after the light is turned on is the radiation intensity of the ultraviolet bactericidal lamp measured.
8、 Attention should be paid to the influencing factors of the quality evaluation of ultraviolet sterilized lamps:
The quality evaluation standard of ultraviolet lamp tube is mainly based on the disinfection technical specification of the Ministry of Health, that is, the relevant regulations on radiation intensity The irradiation toxicity of the lamp tube meets the requirements, and it is bound to have a satisfactory sterilization effect. The factors affecting the over determination of the irradiation intensity of the lamp tube are various: whether the determination conditions in the disinfection technical specifications of the Ministry of Health meet the requirements? Is the ultraviolet radiation meter standard? Does the ballast power deviate? How about the quality of the starter? It is the influence factor of lamp intensity evaluation Attention shall be paid in use.
In addition, the quartz glass tube can penetrate various wave bands of ultraviolet light: glass A, glass B, glass C and vacuum glass, of which 185 nm can produce ozone. When the quartz glass tube is fused, a small amount of titanium oxide (0.01-0.05%) and 0.07% aluminum oxide are added. Ultraviolet light less than 200 nm cannot penetrate the tube wall and be absorbed. The concentration of ozone is too high, which is harmful to human health. Therefore, the low ozone germicidal lamp is used in the working environment Ozone germicidal lamp has both high intensity irradiation and high concentration ozone. It has no dead angle for sterilization and has better disinfection effect. Ozone germicidal lamp can be used in the environment without personnel to improve the sterilization effect In general, different types of ultraviolet germicidal lamps should be selected according to different environments and needs.
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.