Effect of Operating Position on Photometric Performance of HID-Lamp Floodlights

抄録

Photometric performance of floodlights with HID lamps, a high pressure sodium lamp and a metal halide lamp, were determined through different methods and with the operating position varied. The position and the method had no effect on the photometric performance of a floodlight with a high pressure sodium lamp, whereas with a metal halide lamp, they did affect the luminous intensity distribution, leaving the luminaire efficiency intact. The results are considered to have been affected largely by the arc condition of the lamp used in the measurement. Consequently, for an accurate control of the luminous intensity distribution, correct selection of the optical system and of the measurement method are important in consideration of the operating position.