Photoelectric Sensor

Photoelectric Sensor works on the principle of modulated Infra-Red rays. These sensors can sense any opaque, semi-transparent objects which comes in its sensing range. Photoelectric Sensors have large operating distance. 
These are mainly divided into : 
Diffused Beam Sensor, Through Beam Sensor with Amplifier Unit, Through Beam Sensor with Built in Amplifier, Retro-Reflective Sensors.