Inductive sensors are used when the target is metal. These are the most widely used switches in industry today. The inductive proximity switch consists of 4 main components: coil, oscillator, detection circuit and solid state switching device. The oscillator creates a high frequency field that is emitted from the sensing face. When a metal target enters that field, eddy currents are induced in the metal target (hence the term INDUCTIVE). Energy is required from the oscillator to maintain the eddy currents in the target.