Comparison of flicker sensitivity in HPS lamps

The European standard CENELEC EN 50160 establishes that the severity of flicker caused by voltage fluctuations, under normal operating conditions, will not exceed the long term severity Pu = 1 during 95% of the time in one week. This threshold was originally established considering that a lamp with tungsten coiled coil filament of 60 W and 230 V that is gas- filled produces a flicker perceivable by 50% of the population when it is supplied with a voltage that verifies Pu = 1. Other light sources like fluorescent lamps and discharge lamps with ballasts exhibit a different behavior under the same supply conditions. This means that the flickermeter should be different for each type of illumination technique. A test system and a methodology able to measure the optical fluctuation produced by different types of lamps is presented. This experimental platform allows to obtain a correlation between voltage flicker levels and optical flicker perception. It can be considered the first step in the definition of new lamp models and the specification for new electronic ballast design.