Optoelectronic sensor generally consits of an emitter, a detector, and an additional signal conditioning stage.
The emmitter is a pulsed infrared GaAs-diode operating at approximately 900 Nm wavelength with a pulse frequency of 1,5 kHz. The detector is compensated for ambient light to provide protection from false triggering.
The light from the emitter can reach the detector either direct or by reflection.
This can be accomplished in two ways: reflective sensing and light barrier.