EFFECT OF DIMMING ON LAMP LIFE OF FLUORESCENT LAMPS

摘要

With using automatic lighting control it is possible to reduce the use of artificial lighting energy between 30 % and 70 %. If the lighting control system is based on constant horizontal illuminance, the artificial lighting changes according to the quick and large variations of daylighting. The electronic ballasts have to dim the lamps continuously. The effect of dimming on lamp life and the lumen reduction of the fluorescent lamps were studied with lamp life tests. There were 8 test groups in which the lamps were burned undimmed, dimmed to a level 1 %, 5 % or 15 % or dimmed dynamically. In each test group there were fifteen lamps. The static dimming shows that lamps can be burned on low dimming levels without affecting the lumen maintenance. On the contrary, when lamps are burned continuously on low dimming levels, the lumen reduction is smaller than when lamps are burned on full light level. The effect on dynamic dimming has still to be verified in later measurements. The effect of dimming on lamp life and lumen reduction is negligible. The effect of dimming on lamp is thus not an obstacle for wider use of combined use of daylighting and artificial lighting.