10-04-2017, 08:37 PM
Nowadays, the metal detector is used to identify metallic devices such as bombs, guns for security purpose. To avoid any illegal or unauthorized entry of metallic objects, bombs, knives, guns within the luggage bags of the person carrying them in public places like theatres, shopping malls, parks, airports, hotels, railway stations. A security system is developed by using proximity sensor which is named as a metal detector. So, a metal detector is used in many robotic or electronics projects to detect any present metals which are nearby or the existence of hidden items within objects. This article gives an overview of metal detector working principle and applications.
What is Metal Detector?
In the year 1960, the first metal detector was established and was used in industrial applications and mineral prospecting. A metal detector is an electronic device that comprises of an oscillator which generates an AC current that passes via a coil generating an alternating magnetic field. When a part of the metal is nearby to the coil, eddy current will be induced in the metal object & this generates a magnetic field of its own. If an extra coil is used to measure the magnetic field, the magnetic field can be changed and sensed due to the metal object. The metal detectors are used to sense the weapons and also used in the construction industry to identify the steel reinforcing bars in pipes, concrete, wires, pipes buried in walls & floors.
Metal detector types are classified into three types such as BFO (Beat Frequency Oscillation), TR( Transmitter or Receiver) and VLF(Very Low frequency)