Metal detector facts for kids
A metal detector is an electronic device that finds metal objects nearby. These devices are very useful for discovering metal pieces hidden inside other objects. They can also find metal items buried underground. Most metal detectors have a handheld part with a special sensor. You can sweep this sensor over the ground or other things. If the sensor gets close to metal, you will hear a changing sound in earphones. Sometimes, a needle on a display will move. The closer the metal is, the louder the sound or the higher the needle goes.
Another common type of metal detector is a "walk-through" scanner. These are used for security checks at places like airports. They help find hidden metal weapons on a person's body.
The basic idea behind a metal detector is simple. It uses an electronic circuit to create an alternating current. This current goes through a coil, which then makes an invisible magnetic field. If a piece of metal that conducts electricity comes close to this coil, tiny electric currents called eddy currents are created in the metal. These eddy currents then make their own magnetic field. The metal detector has another coil that measures these magnetic fields. When the magnetic field changes because of a metal object, the detector senses it.
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History and Uses of Metal Detectors
The first industrial metal detectors were made in the 1960s. They quickly became popular for finding minerals and for other industrial jobs.
Finding Hidden Treasures and More
Metal detectors have many interesting uses today:
- Finding landmines: They help locate dangerous land mines left behind after wars.
- Security: They are used to find weapons like knives and guns, especially at airports and other secure locations.
- Exploring the Earth: Scientists use them for geophysical prospecting, which means exploring the Earth's surface for minerals.
- Archaeology: Archaeologists use them to find old artifacts buried underground.
- Treasure hunting: Many people use metal detectors as a hobby to search for lost coins, jewelry, and other treasures.
Metal Detectors in Everyday Life
Metal detectors are also used in other important ways:
- Food safety: They help find foreign objects, like small pieces of metal, in food products. This keeps our food safe to eat.
- Construction: In the construction industry, they find steel reinforcing bars inside concrete. They can also locate pipes and wires hidden in walls and floors.
Images for kids
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An early metal detector, in 1919, used to find unexploded bombs in France after World War I
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This 156-troy-ounce (4.9 kg) gold nugget, known as the Mojave Nugget, was found by an individual prospector in the Southern California Desert using a metal detector.
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Metal detectors at Berlin Schönefeld Airport
See also
In Spanish: Detector de metales para niños
