Ifm electronic ogt series diffuse reflection photoelectric sensors 400mm ifm electronic ogt hpkgus this photoelectric sensor is of the diffuse reflection type using the reflections from an emitted light beam to detect objects directly the transmitter and receiver are incorporated into a single m18 x 1 threaded housing with the transmitter using the lower lens and the receiver using the upper lens ifm ogt hpkgus ogt100 diffuse reflective sensor light on