Through Beam Sensors

The through beam sensor is the simplest type of photoelectric sensor, which activates an electrical switch/output signal when a beam of light is detected. Through beam photoelectric sensors consist of two separate units, a transmitter and a receiver. The transmitter unit emits a light beam aimed toward the receiver unit. When an object blocks the light beam, the receiver detects the absence of the beam and triggers the output. Through beam sensors are able to detect materials that are opaque such as wood, metal, plastic, diffused glass, mirrors, and other solid objects. Any object that does not allow light to pass through can be detected by the sensor.