Metal Detector is a device that is used for detecting such metal particles which might not be visible to the naked eye. Metal Detectors were first made in the 1960s, for use in mining and chemical industries.
The working of a Metal Detector is based on the principle of Electromagnetic Induction.
A Metal Detector consists of an oscillator which produces alternating current.
This alternating current passes through the transmit coil of the metal detector and produces a magnetic field around it.
When a metallic object comes in the vicinity of the current carrying coil, a magnetic field is induced around that object. This induced magnetic field interferes with the original magnetic field of the coil.
Then the receiver coil of the detector detects changes in the magnetic field which is caused by the presence of metallic object.
Eventually, an audio signal prompts the presence of metallic object.
Applications Of Metal Detectors:
airport baggage scanner is used at building and airport security check points to make sure that no illegal things are carried inside. For this purpose there are two kinds of Metal Detectors, namely, the Walk-through Detectors and the Wand Detectors. The Walk-through Detector has a metal detecting arch or gate through which people are made to pass. The presence of metallic objects rings an alarm in the Metal Detector. The Wand Detector is a kind of a wand used by the security personnel to check the people by moving it around the body.
Metal Detectors are at times used by the military to detect underground land mines. There are two kinds of landmines used in warfare, antitank and anti personnel. Both these mines can be easily detected with the help of Metal Detectors.
Metal Detectors are also used by treasure hunters for the detection of underground treasures.
It is a wise decision to use Metal Detectors to beef up security on vulnerable sites. Humans have their own limitations and the machines such as Metal Detectors are designed to compensate for these limitations.