Difference Between Reflective, Retro Reflective & Through beam Optical Sensor

Sensors are the very important part of automation industry and are categorized into many types, like proximity sensor, level sensor, pressure sensor, photosensor or optical sensor etc. We widely used these sensor in our industry for object detection, fault detection etc. Sensor are those sensing device which senses and convert that to the electrical signal. In this tutorial we will learn what is the basic difference between a reflective or diffused photo sensor, retro reflective & through beam Optical or photo sensor. Subscribe to Automation-Talk by Email.


Image source: fargocontrols.com

On seeing the above picture, you must have got an idea that what is the difference between these 3 types of optical sensor.

Through beam optical sensor has transmitter and receiver as a separate device and work on the principle that whenever a object comes between transmitter and receiver a signal is sent. Used when sensing distance is large.

Retro reflective type of optical sensor has transmitter and receiver on same housing and they require a reflective surface called reflector for there working.

Reflective optical sensor are also called diffused photo sensor and has transmitter and receiver on same housing but they do not require any reflector for there working. Object to detected itself work as a reflector.

The main advantage of optical sensor's is that they do not do the difference between the object, unlike proximity sensor.