Cylindrical proximity sensors and switches use infrared, acoustic, capacitative, or inductive means to detect objects and will open or close the electrical circuit if the object is within a certain distance. There are three types of proximity sensors: 1) High-frequency oscillation type using electromagnetic induction 2) Magnetic type using magnetism 3) Electrostatic capacity type which senses the changes in the electrostatic capacity between the sensing object and the sensor.
An inductive proximity sensor is a sensing device that detects metal targets using electromagnetic energy and without contact. The sensing range of an inductive proximity sensor changes based on the type of metal being detected. Common applications of inductive sensors include metal detectors, traffic lights, car washes, and a host of automated industrial processes. Because the sensor does not require physical contact it is particularly useful for applications where access presents challenges or where dirt is prevalent.
The two most commonly used proximity sensors are the inductive proximity sensor and the capacitive proximity sensor. An inductive proximity sensor can only detect metal targets. Inductive proximity sensors enable the detection, without contact, of metal objects at distances of up to 60 mm. Their range of applications is very extensive and includes : the monitoring of machine parts (cams, mechanical stops, etc.), monitoring the flow of metal parts, counting, etc.
