American Hawks

Description from WIKIPEDIA

Metal detectors use electromagnetic induction to detect metal. Uses include demining (the detection of land mines), the detection of weapons such as knives and guns, especially at airports, geophysical prospecting, archeology and 'treasure hunting'. Metal detectors are also used to detect foreign bodies in food, and in the construction industry to detect steel reinforcing bars in concrete and pipes and wires buried in walls and floors.

In its simplest form, a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of metal, which is electrically conductive, is close to the coil eddy currents will be induced in the metal, and this produces an alternating magnetic field of its own. If another coil is used to measure the magnetic field (acting as a magnetometer) the change in the magnetic field due to the metallic object can be detected.

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What to do with a metal detector

• When we go to the airport, we pass a security check. You might have seen the security agent use a hand held metal detector when a manual check is needed. So we all know this function.
• You are a handy man and you want to use the old wood you found. Before using your expensive electric saw to cut it, you might need to use a metal detector to see if there are nails inside. Otherwise, you might break your the saw.
• You lost your precious jewelry, coin or other collectable somewhere in the room. Your metal detector will help you find it.
  
• Much much more.
  

Treasure Hunting Code of Ethics:

• Always get permission before searching any site.
• Respect the rights and property of others.
• Observe all federal, state and local laws while treasure hunting.
• Never destroy historical or archaeological treasures.
• Leave the land and vegetation as it was. Fill any holes you dig.
• Use a metal detector ONLY in safe areas.
• Dispose of any junk you find in approved areas. Do not leave it for the next hunter.