Ultraviolet Lamp Radiation Intensity and Ultraviolet Illuminance Meter
1. The radiation intensity of ultraviolet lamps:
In China, the ultraviolet lamps with 70 uw/cm2 (at a distance of 1m) account for almost 50_80%. Compared with the requirements of the safety technical specifications of the Ministry of Health, the pass rate is less than 50%. The radiation intensity of ultraviolet safety lamps used by some units is less than 70uw/cm2 (at a distance of 1m). .Some are still in use even less than 40uw/cm2. You should know that each microorganism has its specific UV killing dose threshold. The 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-term irradiation can obtain the same effect. However, if the ultraviolet intensity is less than 40uw/cm2, then extending the irradiation time can not achieve satisfactory results. There is a problem of microbial damage repair in the middle, and the main purpose is to increase the irradiation intensity
2. Spatial scope of ultraviolet radiation:
Many units that use ultraviolet irradiation lamps ignore the effective space range of ultraviolet radiation, and only consider and calculate the plane area of irradiation. In addition to the area factor, each irradiated space has high and low heights, and the total space range varies. Small, the total space cube should be calculated when using the irradiation lamp, and the ultraviolet irradiation lamp with corresponding power should be used. The effective space range of a 30w irradiation lamp should be less than 30 cubic meters. It is generally believed that the power of the irradiation lamp for each cubic meter of space should be greater than 1-1.5w, it should be noticed in use.
3. Irradiation distance of lamp suspension:
When using the irradiation lamp, you should pay attention to the irradiation distance between the object to be irradiated and the irradiation lamp, that is, the hanging height of the lamp tube should be less than 2.5 meters, and some units that use the lamp tube have a hanging height greater than 2.5 meters, or even greater than 3 or 4 meters. The irradiation intensity is almost inversely proportional to the irradiation distance, if the suspension is too high, it will inevitably affect the irradiation effect.
Fourth, the decline of ultraviolet radiation intensity:
With the prolongation of the use time of the ultraviolet irradiation lamp, the radiation intensity will gradually decline. According to various measurements, the decay rate of the quartz lamp tube is less than 20% after 1000 hours of use, and the decay rate of the high boron lamp tube is greater than 30% after 200 hours of use , plus the radiation intensity of the high boron lamp itself is less than 70uw/cm2, so the quartz ultraviolet irradiation lamp should be used in use. The characteristics of quartz ultraviolet irradiation lamps are mainly high radiation intensity and slow decay. The raw material of quartz lamp tube is natural crystal stone, and the purple transmission rate is more than 80%, while the purple transmission rate of high boron glass is less than 50%. The rate is low, and the radiation intensity is also low.
Five, the application should also pay attention to the wiping and cleaning of the lamp tube:
When using a new lamp, you can wipe the lamp tube with 75% alcohol gauze first, dust and oil stains will pollute the lamp tube. During use, wipe it regularly, and do a good job of cleaning the lamp tube, so as not to affect the purple transmission rate and radiation intensity .
