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

WORKING PRINCIPLE

This device consist of a transmitter and a receiver together. This look alike Inductive Proximity Sensor and hence is also known as IR Proximity Sensor. The emitter emits Infra red rays which are reflected on the receiver through the object to be registered. In the use of these sensors, it is important to bear in mind the colour of the object. Light colour corresponds to the maximum distance and vice versa. In case of shiny object; the effect of surface of object is more important than the colour.

WORKING PRINCIPLE

This consist of two devices; a light emitter and a light receiver. These two devices are kept apart facing each other. The Gallium-Aluminium-Arsenide-Luminescent diode integrated in the transmitter sends pulses of light in the infra-red range which are invisible to the human eye. The receiver opposite to the transmitter receive these rays. Sensing is achieved when these rays are interrupted by the object.

WORKING PRINCIPLE

This is a system which consist of one device and a reflector. The device contains emitter and receiver. The rays emitted by the emitter are reflected by the reflector to the receiver. The sensing of the object occurs when these rays are interrupted.

These block type sensors are available in Diffused, Through Beam and Retro-Reflective types with sensing range varies from 100 mm to 5 Mtrs. The technical specifications are similar to standard cylindrical sensors but useful when mounting space is a constraint.