Metal detectors conjure varied images to many people. To some, metal detectors remind them of the buzzing lights at airport security. Others associate metal detectors with treasure hunting. Some think of handheld scanners used in crowded events such as concerts or sports events.
All of these applications are true. Metal detectors are widely used for different purposes. But what are metal detectors in the first place? The following are some dictionary definitions of metal detector:
– detector that gives a signal when it detects the presence of metal; used to detect the presence of stray bits of metal in food products or to find buried metal
– an electronic device for detecting the presence of metal objects, as one used as a portable sweeping unit or one emplaced in an archway at an airport terminal to detect concealed weapons, explosives, etc.
– A device that senses the presence of metal, especially:
Quite obviously, metal detectors are used to detect metal. These devices are able to do this through the use of electromagnetic induction.
There are several types of metal detectors. These devices are classified mostly by their size, shape and purpose. There are the security metal detectors found mostly in airports and other places that require security check. These metal detectors are stationery and are used to find potentially dangerous items such as guns, explosives, and other weapons so that they will not be brought into restricted areas.
There are also industrial metal detectors. These devices are used mainly in the production process for quality control. These detectors help ensure that products that are shipped do not contain sharp objects like pins and nails. They also measure overall metal content.
Another type of metal detectors are the handheld devices used mainly for exploration, hobby searching, and de-mining in the military. Through the use of electromagnetic induction, these metal detectors can identify metal buried underground or in the water. Because these metal detectors are very portable, some hobbyists bring them to explorations and vacations to find relics and treasures such as old coins.
Metal detectors are used to search for archaeological finds
Other people, on the other hand, find more practical day-today uses for their metal detectors. They use it to find septic tanks, missing tools, equipment, metal pipes, and other buried items. Others use it to find missing jewelries and other valuables while some waterproof detectors could even help find a ring that was lost in the lake or river.
From these applications, we can deduce five five basic types of metal detectors: General Purpose-Coin/Relic/Treasure; Gold Prospecting; Underwater & Salt Beach; Cache Hunting/Deep Searching; and Industrial & Security.
Although manufacturers may design their metal detectors differently, most devices would have the same basic components. There are four key components that metal detectors must have, namely:
• Control box – this enclosure is placed at the top of the metal detector and contains the ‘brains’ of the metal detector- the circuitry, controls, speaker, batteries and microprocessor. Often there is a display unit with a jack for headphones built into the control box.
• Coil – also known as the ’search head’, ‘loop’, ‘antenna’ or ’search coil’, this is the round disc at the bottom of the metal detector that is the sensing part of the unit.
• Shaft – this connects the control box to the coil and is often adjustable so you can set it at a comfortable level for your height.
• Stabilizer- this optional component is usually an arm brace that keeps the unit steady as you sweep the metal detector back and forth.