The Technology Behind The Metal Detectors

Most often you are likely to encounter metal detectors in secure buildings and other important places. Other times guards will instruct you to lift up your arms so that they can scan your pockets with the gadget. The metal detectors are built upon the science of electromagnetism. They would always detect the presence of metals nearby. They are not only used at the security gates but also searching for metallic objects over the ground. They often emit the ‘bleep' sound whenever they are swept over anything metallic.

A metal detector is a special electric instrument used by the military to detect the presence of bombs and other potential threats. So, how does a metal detector work? Electricity and magnetism are like two couples and when you find one, the other will always reveal itself, not very far away. 

The electric appliances we use every day have electric motors that operate in a different way compared to generators. A dynamic magnetic field is generated in a coil of wire which pushes against the permanent magnetic field. This action is what forces the motor to spin. Therefore, it means that magnetism can be used to make electricity and electricity can also be used to make magnetism.

How a metal detector is powered by electromagnetism

There are different types of metal detectors and they both work independently. There is a coil of wire at the end of the handle wrapped around the circular head, often referred to as a transmitter coil. A magnetic field is created when the electricity flows through the coil. If you move the detector over the ground, the magnetic field moves as well. If the detector finds a metallic object, the magnetic field in motion will affect the atoms inside it. In addition, it alternates the movement of the electrons.

To make it easier for you to understand this phenomenon, the metal detector induces some form of electrical activity in the metal. This means that the magnetic field emanating from the detector makes another magnetic field to be revealed around the metallic object. The detector will pick up the second magnetic field that appears around the metal. There is a second coil of wire known as receiver coil which is linked to a circuit that contains a loudspeaker. 

When the detector comes in contact with a metal, its magnetic field cuts through the coil. The science behind this instrument is that when a piece of metal is moved through a magnetic field, the electricity flows through the object the same way a generator operates.

The loudspeaker will then beep or click when the detector goes over the metallic object because the electricity flows through the receiver coil. The closer you bring the detector to the metallic object, the stronger the magnetic field that is created. Therefore, it creates a louder noise because of the more current that flows through it. That is the moment when things start getting serious and you may be found guilty as charged.

How far will the detector go to find a metal object?

There are several factors which determine the effectiveness of the metal detector. These include;

• The shape, size, and type of the metal object buried underneath. It will be easier to detect the larger objects compared to the small ones.
• The nature of the sand or surrounding soil
• Things that have stayed on the ground for a long time might have been oxidized or undergone corrosion.
• The orientation of the metallic object also matters depending on their surface area. Generally, it is easier to find objects that were buried flat in the ground compared to those that face downwards or upwards. 

Various uses of metal detectors

Most of the metal detectors have been used at airports in the walk-through scanners. That is the reason they can detect metallic items such as earrings, buckle, bracelet, and others. They have also been useful in fighting crimes by detecting illegal items such as guns, knives or other life-threatening items. You will find them in different shapes and sizes to suit the purpose for which they are intended.

Final Thoughts

In conclusion, metal detectors are useful electric instruments that help to detect metallic objects. It would be difficult to fight more crimes if we never had various types of detectors. Different companies have enhanced the technology used in the detectors to enable them to find the tiniest pieces of metals hidden in the ground. The walk-through metal detectors also offer convenience i.e. at the airports. These devices would always flash out any type of metal using their electromagnetism capabilities.