Workings of metal detectors by electromagnetic induction

electromagnetic induction

Metal detectors are used for various purposes to detect metals by the principle of electromagnetic induction. A perfect metal detector has four parts that are comprised of control box where lies all control, batteries and the circuit. The other parts are search coil that actually is a metal sensor, a shaft that connects the coil and the control box, and the last part of the metal detector is a stabilizer. Stabilizer controls the flow of current passing through it and keeps it in a steady position. As most of the metal detectors are lightweight and hand-held, the stabilizer is used during sweep motion to keep the current steady.

Operation of metal detectors for metal detecting

To detect a metal at first, metal detectors should be kept switched on. Once the metal detector is turned on, it is easy to detect metals. You just need to pass the best metal detectors over the search area slowly. The units will slowly move over the search area in a sweeping motion. In this process, the current will be produced by the oscillator that will pass through the search coil, and the coil will produce a magnetic field. If the metal with conducting properties is present near the metal detector over the search area, then a current is induced named “Eddy Current”.

This will cause the alarm of the metal detector to buzz, and this audible signal will help to indicate the presence of metal over the search area.

There are three technologies from which the detectors can fall in, and they are beat-frequency oscillation, very low frequency, pulse induction. In today’s era, the most preferred technology is very low frequency. This detector is used in detecting archaeology, silver and gold prospecting, treasure hunting, and relic, and most commonly used for security purposes. It also used in food, chemical and pharmaceutical industry that establishes metal combination in production lines.