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Metal
Detectors , metal detecting
, metal detector, treasure , treasures , treasurehunting ,
treasure hunting
Metal detectors use an electromagnetic
induction in order to detect metal. Uses include de-mining (the
detection of land mines), the detection of weapons such as
knives and guns, especially at airports, geophysical
prospecting, archaeology and treasure hunting. Metal
detectors are also used to detect foreign bodies in food,
and in the construction industry to detect reinforced steel bars in concrete and pipes and wires buried in walls and
floors.
In its simplest form, electronic surveillance metal detector consists of an
oscillator producing an alternating current that passes
through a coil which produces 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 , buried treasure, can be detected.
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Inductive
sensor
An inductive sensor is an electronic proximity sensor, which
detects metallic objects without touching them.
The sensor consists of an induction loop. Electric current
generates a magnetic field, which collapses generating a current
that falls asymptotically toward zero from its initial level
when the input electricity ceases. The inductance of the loop
changes according to the material inside it and since metals are
much more effective inductors than other materials the presence
of metal increases the current flowing through the loop. This
change can be detected by sensing circuitry, which can signal to
some other device whenever metal is detected.
Common applications of inductive sensors include metal
detectors, traffic lights, car washes, and a host of automated
industrial processes. Because the sensor does not require
physical contact it is particularly useful for applications
where access presents challenges or where dirt is prevalent. The
sensing range is rarely greater than 2 cm, however, and it has
no directionality.
Famous treasure hunters
The salvage of the shipwreck RMS Republic - Capt. Martin Bayer
located the RMS Republic in 1981. His is a story of a very real
quest/treasure hunt for what may be the greatest lost shipwreck
treasure of all time.
treasure hunting is very common in some islands
like Australia, England and Newziland Where you can find silver
,gold ,coins ,jewelry ,relics, ring, coin shooting , coin
shooting
Dr. E. Lee Spence (pioneer underwater archaeologist, author of
real life adventure articles and former editor for a number of
magazines, discoverer of American Civil War submarine H. L.
Hunley and numerous other wrecked vessels. metal detecting Spence has salvaged
over $50,000,000 dollars in artifacts and has been responsible,
through his archival research, for the recovery of over one
billion dollars in gold and silver coins or buried treasure from the wrecks of the
side-wheel steamers Republic and Central America.)
Mel Fisher
Robert F. Marx (underwater archaeologist, author)
Robert Seniti (underwater archaeologist, author)
Heinrich Schliemann (grocer turned treasure hunter, considered
father of historical archaeology, discoverer of lost city of
Troy)
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