forfaringssett for photoelectric bestemning of grensskiktet in a light bundle from a automobilstralkastare or similar and device for utovande of forfaringssettet

摘要

The invention relates to methods and devices for determining the position of the cut-off of the light beam from a motor vehicle headlight. A pair of light detectors Dc and D1 are located on a screen and the headlight and screen moved relatively to one another until the light intensities Ic and I1 satisfy the relation Ic = aI1 + b WHERE A AND B ARE GIVEN PARAMETERS SUCH THAT WHEN THE SAID RELATION IS SATISFIED, THE POSITION OF THE CUT-OFF IS INDICATED BY THE POSITION OF THE DETECTING SYSTEM Dc.