How a Metal Detector Works

Metal detecting is becomingĀ one of the most popular hobbies in recent times. A lot of people are takingĀ up this hobby and even making money off of it.

You are going to be surprised at just how much you can dig up from the ground that can actually turn out to be more valuable than you may think.

If you are interested in getting into this wonderful hobby, whether it is for money or if you are feeling adventurous, then you have to know how metal detectors work.

In this article, we are going to give you the basic information on how a metal detector works and what you can do, as a novice, to learn as much as possible so you can take your first step into detecting metals.

Very Low Frequency.

VLF or Very low-frequency work on the principle of conductivity. Most metal detectors will work on the principle of conductivity. Electromagnetism occurs between electrically charged particles.

When the search coil passes over a metal object with a conductive surface; whether the object is on the surface or 18″ below ground. A signal or tone is heard due to the electromagnetic field generated.

The electromagnetic field is directed from the search coil into the ground. As these electromagnetic lines penetrate the ground the electromagnetic field hits the metal object.

Once this happens the metal object creates its own electromagnetic field or eddy which in turn is reflected from the object in many different directions.

The coil then receives the ones that are sent up to the surface. This signal is then sent to the discriminator meter then a tone or target ID is generated. The better the tone or number the better the target.

Metal detectors and electromagnetism.

A metal detector uses electromagnetism to detect metals. One of the simpler methods of powering it is through the use of a wrapped coil of wire on the head of the handle of the device.

This is what you call a transmitter coil. If and when the electricity flows directly through the wrapped coil, a magnetic field is created in the surrounding area.

When you sweep around the ground, it essentially makes the magnetic field hover around the particular areas as well. Moving the metal detector on top of a metal object, even if it is buried underneath, it will pick up all of the electromagnetic or eddy’s produced from the metal object.

With this, you will be able to detect that there is, in fact, metal under the ground through the work of the receiver coil. This coil is the second coil of wire that is wrapped inside the search coil of the metal detector.

It is, more often than not, connected to a speaker, and if magnetic signals are received by the coil before it is transmitted to it, it will give off a tone to notify you that there is metal in the ground.


As you can see, electromagnetism plays an important role in making sure that your metal detector is as efficient as possible. Thankfully, manufacturers are finding more and more ways to make sure that metal detectors are technologically advancing.

You will see a range in this by the models you select. Different models have different frequencies. They range from 6.5 kHz to 100 kHz

You will see even more features and advances in newer models of metal detectors, due to the constant desire for more accuracy and sensitivity in detecting the metals that are hidden underground.

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