How Does a Metal Detector Work?

How Does a Metal Detector Work


How Does a Metal Detector WorkMetal detectors first came into prominence during the world war. They were used to effectively detect and avoid enemy mines. Since then, their use has greatly evolved. In addition, the technology used in these devices has been greatly upgraded. Now hobbyists use them for treasure hunting. A good metal detector can change one’s fortunes so make sure to pick the best metal detector for the purpose and read metal detector reviews before you start on your hunt.

How Does It Work?

A metal detector works using a very basic concept. IT works on the concept of electromagnetism. This concept develops more than a century ago, states that electricity and magnetism are interconnected. In fact, each can be used to generate the other. Today, the concept is applied in a number of areas. For instance, in the airport and stadium security, these devices are used to detect the presence of metallic objects on people.

When a person is using a metal detector, they are transmitting a signal into the ground, which is about two feet deep. This signal is designed to interact with any metallic object that is located inside the earth. When the magnetic field comes into contact with a piece of metal, as it stimulates electrons within this metallic object. As a result, this metallic object generates a tiny electric current.

How Does a Metal Detector WorkThe electronic current is what another coil located within the head of the metal detector detects. This coil is known as the receiver coil. However, the received current is obviously very weak. In order to increase the chances of it being heard, it is passed through an amplifier. The amplified signal is the transmitted to speakers located higher up on the metal detector. This is how the user knows if there is a metal object in the earth. It is important that the metal detector works mostly on surface area and not mass. For instance, if a coin is lying flat it will have a stronger signal than one that is upright.

This means that even in instances where one detects a weak signal it should not be ignored. The metal detector hovers over the area until one can pinpoint where it is located. Tilting the metal detector slightly when trying to pinpoint the target can help boost the signal.

Challenges Faced

One of the biggest problems one will face is ground interference; this is especially true in an area with high mineral content. For instance, when searching on a beach, the minerals from seawater generate a constant interference. However, the signal generated by the sand is relatively stable. This has enabled developers to come up with something called ground balance. The metal detector is set to ignore the ground interference, which is stable over a wide area.

Another issue faced by metal detectors is discrimination. One may end up digging for worthless objects all day such as old nails and bottle tops. The best way to avoid this is to purchase a metal detector with discrimination. These detectors are designed to indicate the type of mineral depending on the signal. This is made possible through a microchip processor.


That is how most modern metal detectors work. Except for a few upgrades, the technology has scarcely changed. When purchasing one, it is important to understand all the functionality possible with most metal detectors.