Iron Discrimination - Minelab GP Extreme User Manual

THE MINELAB 'GP extreme'
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Figure 5.2 Setting the ground balance
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GROUND BALANCING
Ground Balancing Procedure
Figure 5.2
• Move the coil up and down between 20mm and 100mm above
the ground and, while moving the coil, change Balance from
Fixed to Tracking.
• The fast ground balance takes only 5 sec. after switching to
Tracking. Therefore, it is important to be moving the coil as the
switch is changed.
• Keep moving the coil until all ground noise has stopped. A
persistent signal may indicate a target in the ground.
• If this occurs, then move the coil to a new location and repeat
the procedure.
• When there is no longer a change in the threshold, while the
coil is being raised and lowered, the detector is 'ground
balanced'.
• When the detector has been ground balanced, the user may
select either Fixed or Tracking for detecting.
If the ground is mineralised or variable, use Tracking.
If the ground is very 'mild', use Fixed and switch back to Tracking
temporarily if the threshold becomes noisy. Do not test a target by
switching to Tracking when the coil is above it.
HINT It may useful to repeat the ground balance procedure if
ground conditions change rapidly.

IRON DISCRIMINATION

Discrimination is the ability of a detector to distinguish between different types of
metal objects and to assist the user in identifying a target.
Some goldfields are littered with 'rubbish', e.g. metal objects which are of little
value and are an annoyance to detector users.
The 'GP extreme' is capable of rejecting many iron objects while still detecting non-
ferrous metals. The ability of the detector to discriminate ferrous targets means
that, while detecting in littered goldfields, much of the iron rubbish may be ignored,
with a high probability that valuable targets will not be missed.
Figure 5.3 Discrimination levels
THE MINELAB 'GP extreme'
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P0507-A
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IRON DISCRIMINATION