Theory or Operation of Inductive Proximity Sensors | How Inductive Proximity Sensor Works? In this section we will look at Inductive proximity sensors , and how they detect the presence of an object without coming into physical contact with it. Inductive proximity sensors are available in a variety of sizes and configurations to meet varying applications. Specific sensors will be covered in more detailed in the following section. Electromagnetic Coil and Metal Target The sensor incorporates an electromagnetic coil which is used to detect the presence of a conductive metal object. The sensor will ignore the presence of an object if it is not metal. Inductive proximity sensors are operated using an Eddy Current Killed Oscillator (ECKO) principle. This type of sensor consists of four elements: coil, oscillator, trigger circuit, and an output. The oscillator is an inductive capacitive tuned circuit that creates a radio frequency. The electromagnetic field produced by the os...