KJT slot-type photoelectric switch is actually a kind of through-beam photoelectric switch, also called U-shaped photoelectric switch. It is an infrared sensing photoelectric product, which is composed of an infrared transmitter tube and an infrared receiver tube. The slot width is It determines the strength of the induction receiving model and the distance of the received signal. Light is used as the medium, and the infrared light between the luminous body and the light receiving body is received and converted to detect the position of the object. The trough photoelectric switch is also non-contact like the proximity switch. It is less restricted by the detection object and has a long detection distance. It can detect long distances (tens of meters) with high detection accuracy and can detect small objects. The application is very wide.