For use with counters, CASSY (
524 013,
524 006,
524 005W,
524 018) or the universal physics measuring instrument (
531 835).
With adjacent light transmitter and receiver. A white or reflecting object is detected in front of the light barrier. Unaffected by ambient light due to light modulation. Can be used, for example, for measurements of rotary frequencies, e.g. on a gyroscope, also in experiments in which a forked light barrier cannot be easily mounted.