Design & Development of Ruggedized Mechanism for Detection of Rotating Metallic Objects Using Inductive Proximity Switches

We describe a sensing arrangement for detection of a metallic body rotating at high revolutions per minute (rpm) operating in dusty and muddy environment. For such an environment, the sensing range, switching frequency & ruggedness of proximity switch are key parameters. When an electrical conductor, such as a metal target enters the electromagnetic field, eddy current starts circulating in the conductor. This eddy current draws energy from the field. Presence or absence of metallic objects can be detected by measuring the energy deficit because of the eddy current. An inductive proximity switch based system was developed for detection of rotating metallic objects. Experiments were carried out in the simulated dusty & muddy environment to check the functionality of the system. It has been planned to install the inductive proximity switch based system for detection of metallic objects rotating at high rpm in military application.