WHAT METALS CANNOT BE DETECTED BY A METAL DETECTOR?

If you’ve ever had an interest in treasure hunting, you’ve likely seen metal detectors before. While they may seem like a full-proof way to find valuable treasures lying underground, they do have their limitations.

Read on to learn what metal detectors are, how they work, and metals that they will not be able to detect.

What Is A Metal Detector?

Metal detectors are electronic devices that use a large coil of wire, known as a transmit coil, and a second coil of wire, also called a receive coil, that alerts you to the presence of buried metals by emitting a sound.

However, metal detectors can’t find everything that lies underground.

Metals That Can’t Be Detected

Metal detectors work on electromagnetism. This means that they send out electromagnetic fields and listen for any waves that come back from items with electrical conductivity.

Metal detectors have a tough time detecting metals like stainless steel, which have very poor electrical conductivity. Stainless steel has low magnetic permeability, which means it does not produce a signal strong enough to be detected. Other items that metal detectors won’t be able to locate include:

• Gemstones
• Paper
• Pearls
• Bone
• Stone figures

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Metals That Metal Detectors Can Easily Find

Ferrous metals are the easiest for metal detectors to find due to their magnetic properties. If the metal is conductive, then the chances a detector will find them are high.

Using The Discrimination Feature

Metal detectors can’t be set to find exact types of metals and alloys. However, there is one feature you can use to avoid detecting unwanted items.

Metal detectors come with a discrimination setting that can differentiate between metallic alloys. As different metal objects have their own characteristic phase shift, it’s possible to tell the difference between them. Silver dimes will generally cause a larger phase shift than aluminum for example.

• by Manhattan Gold and Silver