How do metal detectors only sense metal?


I’ve always wondered how they are able to pick metals up on the scanner and not other materials

In: Technology

They’re looking for materials that interact with a magnetic field. Out in nature, this is almost always a conductive metal.

There are other materials that react to or interfere with the magnetic field and could produce a false reading, but they’re pretty rare.

You’re unlikely to stumble across a deposit of magnetic ore or some kind of human-made conductive ceramic while checking the beach for jewelry.

Ferro metals!

It’s using magnetism. That’s why you have these disk shaped, and even hollow circles. Current flows through there, creates a magnetic field.

If any ferro-metal is in the ground it disrupts the magnetic field and the operator gets a signal