Problems with irradiance of UV lamps
China's ultraviolet lamps 70 uw/cm2 (1m distance) accounted for almost 50_80 per cent, against the requirements of the Ministry of Health safety specifications, the pass rate of less than 50 per cent. Some of the use of ultraviolet lamp irradiation intensity less than 70 uw/cm2 (1m). Some even less than 40uw/cm2 still in use. It is important to know that each micro-organism has its own specific ultraviolet killing dose threshold. The dose (K) is the product of the irradiation intensity (I) and the irradiation time (t), K=It. From this equation, it can be seen that high intensity short time or low intensity long time irradiation can be obtained with the same safety effect. However, if the ultraviolet intensity is less than 40uw/cm2, then extend the irradiation time can not play a satisfactory safety effect, which exists in the middle of the microbial damage repair problems, intentionally to improve the irradiation intensity of the main
Ultraviolet irradiation of the spatial scope of the problem:
Many ultraviolet lamps use units to ignore the effective spatial range of ultraviolet irradiation, only to consider and calculate the plane area of irradiation. Each space, in addition to the area factor, the height of the high and low, the total spatial range of large and small, the use of irradiation lamps should be calculated for the total space cubic using the appropriate power of ultraviolet irradiation lamps, a 30w irradiation lamp effective spatial range should be less than 30 cubic feet.
Lamp hanging irradiation distance:
The use of irradiation lamps should pay attention to the irradiation distance between the irradiated object and the irradiation lamp, i.e., the lamp should be hung at a height of less than 2.5 metres, some of the units using lamps hung at a height of more than 2.5 metres, or even more than 3, 4 metres are available. UV irradiation intensity and irradiation distance is almost inversely proportional to the suspension is too high, is bound to affect the effect of measurement.
