Abstract: Objective  To evaluate the radiation efficiency of a kind of ultraviolet germicidal irradiation (UVGI) system at upper room.  Methods  In an simulation ward and clinic equipped with “SINOVO^TM constant indoor air sterilization system”, to measure the radiation intensity in the following points: 1.0 m ahead of the system, 0.5 m, 1.0 m, 1.5 m to the left and right side of the system, 4.8 m of the opposite wall, and upper and lower 5 cm and 10 cm of each points mentioned above, and also the facial radiation strength and dose of 1.7 m height people. The intensity over 10 μW/cm² is effective germicidal strength, and radiation doses of less than 0.2 μW/cm² is safe dose.  Results  The radiation intensity is 427 μW/cm² 1.0 m distance ahead of “SINOVO^TM constant indoor air sterilization system”, 56 μW/cm² and 58 μW/cm² in its left and right sides (1.5 m) close to the walls,179 μW/cm², 111 μW/cm² and 70 μW/cm² 1.5 m, 2.0 m ahead and 4.8 m at the opposite wall.  Conclusion Upper room UVGI system is a safe, efficient disinfection tool which could apply to infection control of respiratory infectious diseases, especially for tuberculosis.

Key words: Tuberculosis/prevention &, control, Ultraviolet , rays, Disinfection, Patients&, rsquo, rooms, Radiation effects