Product Description: Beam Sensor – Photoelectric beam systems detect the presence of an intruder by transmitting visible or infrared light beams across an area, where these beams may be obstructed. To improve the detection surface area, the beams are often employed in stacks of two or more. beam sensors detect and count small parts, detect the edges of objects and monitor passages in systems. The emitter and receiver are housed in separate housings according to the through-beam mode. The sensor switches as soon as an object interrupts the laser light, red light or infrared light.