Luminaire with sensor for the detection of soiled, aged and / or broken photometric covers

摘要

The invention relates to a lamp comprising at least one light source, a transparent cover which at least partially covers the light source from the surroundings of the lamp, a light sensor which is arranged to measure an intensity of light emanating from the light source and from the cover is reflected back directly or indirectly, and a control unit which is set up to determine a difference between time-related measured values of the light sensor in order to indicate a change in the degree of reflection of the cover when a threshold value is exceeded.