Ground Balance Procedure For Tracking - Minelab GPX-4500 Instruction Manual

Ground Balance Procedure
40
for Tracking
(For Ground Balance Type – General)
Ground 1 Find a clear area of ground without any targets.
Balance
2 Change the Ground Balance switch to Fixed.
Fixed
3 Whilst keeping the coil parallel to the ground, lower
and raise the coil between 25mm and 100mm
Ground
(1" and 4") over the ground. Try to lower the coil as
Balance
Tracking
close to the ground as possible without touching it.
Fixed
4 While moving the coil change the Ground Balance
switch to Tracking and continue moving the coil
up and down until the audio has stabilised and any
Tracking
ground noise has stopped.
Note: A persistent signal may indicate a target in the
ground. If this occurs, move the coil to a new location
and repeat the procedure.
5 When there is no longer a change in the Threshold,
the detector is 'Ground Balanced', and you can
commence detecting.
Note: When changing the Ground Balance switch from
Fixed to Tracking a very fast auto-Ground Balance is
initiated prior to returning to a normal Tracking speed.
This fast Ground Balance only lasts a short time, so
it is important to be moving the coil before changing
the switch.
100mm (4")
Ground Balance reset in Tracking
Whilst sweeping the coil you should periodically
test that you are still in harmony with the ground by
stopping, then raising and lowering the coil. If the
Threshold remains stable then you are still Ground
Balanced. If there is a change in the Threshold then
you need to reset the Ground Balance setting.
While raising and lowering the coil press and release
the Quick-Trak button. A short 'beep' will be heard
which lets you know that a three second, fast
auto-Ground Balance is initiated prior to returning
to Tracking. Once the audio has stabilized you can
continue searching.
If you find that the Ground Balance needs to be
reset quite regularly, you can select a Faster Tracking
speed. Three Tracking speed options
available from the LCD menu.
Note: In highly variable
ground the Tracking may
not instantly update the
GB setting when you detect
over a large mineralisation
change; so there may be
a period of time where
you will experience some
ground signals. To avoid
missing any faint target
signals you may have to
reset the ground balance
(pg. 76) are
As Tracking continually updates the Ground
Balance setting, repeated passes over a
target may result in the detector balancing
to the target instead of the ground;
diminishing the target signal and increasing
ground noise.
Therefore, it is important to use Fixed
when pinpointing or when investigating a
potential faint signal with repeated sweeps.
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