Metal detectors are designed by definition to detect hidden metal.

But they might have instruments for detecting metal.

The loris shows them how it detects metal with Barlow's necklace.

These are magnetic field generators that are able to detect metal when it passes into the field.

I'm trying to detect metal under the ground.

You don't have to detect metal to fix a drive.

The portals that screen people at the airports only detect metal.

The general tells him what it is for and that it can also detect metal.

Looked to me like a magnetometer for detecting metal.

If it detects both metal and wood, like a nail in a stud, it shows both icons.