Treasure Hunting

How Do Metal Detectors Work?

Are you wondering how do metal detectors work? This question is one that many people are asking. Indeed, even we can’t help but wonder how a device can locate metals and other valuables like gold and silver.

Metal detectors may look simple devices at first glance, but the inside mechanism is extremely complicated. Today, we’ll talk about this awesome innovation and its main purpose in the industry.

What Is a Metal Detector?

When you hear “metal detector,” what is the first thing that comes to your mind? Most people would say that they think of it as a device used to look for buried coins, jewelry, or treasures. Others would think of the device used by security personnel to check our bodies and our belongings when entering malls or airports.

Basically, both are true; the devices described above are both metal detectors. You may use a metal detector to look for lost jewelry or coins around the house, or you can use it to locate metals buried underground. And, yes; those things used by security guards to scan our body are also considered metal detectors.

Parts of a Metal Detector

In order to understand how do metal detectors work, we first need to get to know the basic parts that make up one. Below, we would be focusing on regular metal detectors used for treasure hunting.


Some metal detectors have stabilizers; others don’t. The main function of this part is to keep the unit steady while you are sweeping it back and forth, trying to look for coins and other metals.

Control Box

The control box is the part of a metal detector that holds the controls, circuitry, batteries, speakers, and, of course, the microprocessor.


The shaft is the part that would connect the control box and the coil. This can be adjusted to the height that you want; you can lengthen or shorten the shaft depending on your preference.

Search Coil

This is more like the antenna of the metal detector, and it is responsible for detecting the metal on the ground.

How Do Metal Detectors Work?

Metal detectors are very complicated. Although they are very easy to use following our guide. The processes that are happening inside that small device are actually very intricate. Before we find how do metal detectors work, how do you use one anyway?

Of course, the first thing you need to do is to turn the unit on. Then, move the detector slowly while walking. You can slowly bring it to a certain location, and you can sweep the coil back and forth on the ground.

An audible signal will happen if you pass it over a target object. Advanced metal detectors can actually pinpoint the metal that it has detected, and it would indicate the depth of the targeted object as well.

Pretty simple, right? This is just the basic method of using a metal detector, and it contains so many features that you would need to spend a lot of time learning about. Now, let’s proceed with the process of how do metal detectors work.

  • After turning the metal detector on, the battery would activate the transmitter circuit inside. It will then pass down the electricity through the cable from the handle towards the transmitter coil at the bottom.
  • Once the transmitter coil receives the electricity, it will then create a magnetic field around the coil. The magnetic field will serve as the antenna; it would search for metals on the ground.
  • If you try to sweep the metal detector to a certain metal, the magnetic field from the coil will seep through it. It will then create an electric flow current in the metal object that you targeted.
  • The flowing current will then create another magnetic field around the object. The signal will then be sent through the receiver coil, and it will move it up to the receiver circuit.
  • When this happens, a buzzing sound will be released by the metal detector, indicating that you found a certain metal.