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LCD Visual Display
In normal operation, when the search coil passes over a metal object, the electrical signature
(2-digit I.D.) of the metal object is displayed on the numeric display for 4 seconds, unless
superceded by another detected object. On a given buried object, the number will bounce
around if the signal is weak or if the amount of ground mineralization is high.
At the top of the display, a block illuminates to indicate the classification of the object.
NUMERIC TARGET I.D. (2-digits)
The following table shows the numbers typically associated with certain commonly
encountered nonferrous metal objects. Older silver U.S. coins usually read about the same as
their modern clad equivalents. Modern quarter-sized dollar coins like the Susan B. Anthony
and the Sacagawea read about the same as a quarter. Many Canadian coins are minted from
a magnetic nickel alloy which gives very inconsistent readings and may register as iron. Most
one-ounce silver bullion coins will fall into the same range as the modern U.S. $1 Eagle.
OBJECT
foil from gum wrapper
U.S. nickel (5¢ coin)
aluminum pull-tab
aluminum screwcap
zinc penny (dated after 1982)
aluminum soda pop can
copper penny, clad dime
U.S. quarter (25¢ coin), clad
50¢ coin, modern clad
old silver dollar coin
US silver Eagle $1 coin
PROBABLE TARGET I.D.
The probable target ID zones at the top of the LCD display represent the signal ranges
produced by various coins and types of metal objects. When a metal target is detected, the
microcomputer analyzes the signal and categorizes it based on what kinds of metal objects
usually produce that kind of signal. The
microprocessor then displays a block
along the top of the LCD screen above
corresponding category.
For instance, if the detected signal fits
within the parameters usually exhibited
by zinc pennies, the microcomputer will
categorize the signal as "zinc penny".
The LCD screen will then illuminate the
block above the "ZINC".
Copper pennies (pre-1982) will usually register in the DIME zone.
Most gold jewelry is small, and will tend to read in the 16-55 range. Silver jewelry usually has
more metal in it and therefore tends to produce higher readings.
TARGET I.D.
16-25
typically 30
33-55
60 - 70
typically 60
most often 63-69, but can vary widely
typically 70
typically 80
typically 86
typically 90
typically 91
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