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Metal detectors work due to the fact that
metal is conductive. Metal detectors create
an electromagnetic fi eld, which penetrates
the ground.
When the coil senses a change in this fi eld
(caused by a metal object) it sends a signal
back to the control box which then alerts
the operator. Metal detectors react to the
size, shape and composition of objects.
Typically, the larger the object, the deeper
it can be detected.
The X-Terra uses a single frequency (7.5kHz)
as the standard operating frequency. This
frequency has the ability to penetrate deep
into the ground.
The frequency of a detector is the number
of times a signal is transmitted into the
ground and received back, per second
(measured in Hertz - Hz).
The X-Terra has a number of diff erent icons
that have been designed to best represent and
identify the metal objects in the ground.
Target ID
Buried metal objects are referred to as targets.
As the coil is passed over a target, it detects
its conductivity and displays this as a number.
Target Identifi cation (ID) is used to distinguish
one type of metal target from another.
Target ID numbers range from -4 to 44 on the
X-Terra 30 and -9 to 45 on the X-Terra 50.
Negative numbers represent ferrous targets and
positive numbers represent non-ferrous targets.
The last detected target ID stays on the
display until another target is detected. If the
detector passes over a target that it rejects, the
display will return to a blank detection screen
represented by 2 dashes.
Depth indicator
A guide to how deep a metal
Target ID
object is under the ground.
The numeric identifi er
The more arrows displayed,
of a particular metal object
the deeper the object is likely
underneath the ground.
to be from the coil.
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2
Discrimination segment
Another identifi er of metal objects, each segment
refers to a certain type of metal signal. Segments
can be turned off (to accept targets) or turned on (to
reject targets) which in turn accepts or rejects signals
from the corresponding metal objects.
(A grey icon on the diagrams in this manual
represents a fl ashing icon on the detector.)
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