Spectroscopic Analysis of Ultraviolet Lamps for Disinfection of Air in Hospitals

In order to have feasibility study of ultraviolet lamps for air disinfection in hospitals, a number of lamps were studied spectroscopically. It was required to understand if these lamps really emitted 253.7 nm. Was the radiation intense enough to disinfect the surrounding air in the hospital? And to know about the percent transmission of the UV rays through the glass of the lamps. The intensity and UV dose were calculated at various distances in air from the lamps. While putting 1-min exposure time in the reciprocity law, the intensity/distance and dose/distance graphs were drawn for various lamps. From the trend line of the graph the distance at which the lamp emitted 10 μW/cm² was calculated. In this study the 1-min exposure time was considered, using the Riley’s designed upper room air disinfection data for 90% kill rate. In the light of the results these lamps were considered fit to be installed either in the air ducts or in the upper room at certain distances for air disinfection, and suggestions were given for the improvement of the system proposed.