User's Manual

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TEKNETICS
Comprehensive Operating Manual & Guide to Metal Detecting
TEKNETICS
Comprehensive Operating Manual & Guide to Metal Detecting
CAPABILITIES AND LIMITATIONS
DEPTH
The T
2
can detect U.S. coins to a depth of about 12-15 inches under good conditions. Large
objects (55 gallon drums, manhole covers, etc.) can be detected to a depth of several feet.
Electrical interference from power lines and from electrical appliances and electronic
equipment can reduce detection depth, or cause audible interference, making it necessary for
the user to reduce the sensitivity setting. Soils with large amounts of iron or salt minerals
may also reduce detection depth or necessitate a reduction in the sensitivity setting.
TARGET IDENTIFICATION
The T
2
identifies the probable type of metal object by measuring its effective electrical
conductivity, which is displayed as a number from 0 to 99 on the LCD screen. The
effective
electrical conductivity
of an object depends on its metallic composition, size, shape, and
orientation relative to the searchcoil. Since coins are minted to tightly controlled specifications,
they can be accurately identified. Identification of pull-tabs and foil is less consistent because
these kinds of targets come in wide variety. In general, smaller objects, and objects made
from lower conductivity alloys such as iron, bronze, brass, lead, pewter, and zinc will read
lower on the effective conductivity scale. Larger objects and objects made from higher
conductivity alloys such as silver, copper, and aluminum, will tend to read higher. The notable
exceptions are gold, which usually reads low because it is rarely found in large pieces, and
zinc pennies, which read moderately high because of their size and shape. Although nails and
other iron and steel objects will usually give low readings, ring-shaped pieces of iron (for
instance steel washers and harness rings) will usually produce medium to high readings. Flat
pieces of iron or steel, such as can lids, will occasionally do the same.
Most targets can be identified accurately in air to a distance of about 10 inches. The minerals
in many soils will cause identification to be less accurate. In most soils, effective Target
Identification can be had to a depth of at least 8 inches.
REQUIREMENT FOR MOTION; PINPOINT FEATURE
As with other modern metal detectors, the T
2
’s searchcoil must be kept in motion in order to
both detect and identify targets. The All Metal Mode is more forgiving of sweep speed
variation than is the Discrimination Mode.
The trigger-activated PinPoint feature continues to detect metal if searchcoil motion stops over
the target. The PinPoint feature is used primarily to pinpoint the exact location of a target so
that it can be retrieved with a minimum of digging, and does not provide Target Identification.
LCD VISUAL DISPLAY
In normal operation, when the searchcoil passes over a metal object, the electrical signature
(2-digit ID) of the metal object is displayed on the numeric display for 4 seconds, unless
superceded by another object sooner. 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, an arrow indicates the classification of the object.
NUMERIC TARGET-ID (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 TARGET-ID
foil from gum wrapper 40 - 55
U.S. nickel (5¢ coin) typically 58
aluminum pull-tab 60 - 75
aluminum screwcap 70 - 80
zinc penny (dated after 1982) typically 78
aluminum soda pop can 75 - 85
copper penny, clad dime typically 83
U.S. quarter (25¢ coin), clad typically 89
50¢ coin, modern clad typically 92
old silver dollar coin typically 94
US silver Eagle $1 coin typically 95
PROBABLE TARGET-ID
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 an arrow along the top
of the LCD screen above the icon which represents that category.
For instance, if the detected signal fits within the parameters usually exhibited by zinc pennies
and the electrically similar aluminum screwcaps, the microcomputer will categorize the signal
as “zinc penny/aluminum screwcap”. The LCD screen will then illuminate the arrow above the
zinc/screwcap icon.
Copper pennies (pre-1982) will usually register in the 10¢ zone.
Most gold jewelry is small, and will tend to read in the 40-60 range. Silver jewelry usually has
more metal in it and therefore tends to produce higher readings.
Since different metal objects can produce similar signals, and since minerals in the soil can
distort the signals, the probable Target-ID’s are just that — probable. There is no way of
knowing for sure what’s buried other than to dig it up. Experienced metal detector users have
a rule of thumb — “when in doubt, dig”.
STRONG MEDIUM WEAK