IDENTIFYING TARGET SIGNALS
Pinpointing
To find an object and reduce the size of the hole required to remove it from
the ground, it is necessary to pinpoint the exact location of the object.
If a target is heard, first confirm it by setting an accurate ground balance and
then pinpointing. To ground balance, change the Balance switch to
Tracking and pass the coil around the area of the target, making sure that
the target is not detected (keep the coil away from where the target is).
While the coil is moving around the area of the target, change
Balance to Fixed. This will give a very accurate 'ground balance'
on this area. One of the pinpointing techniques may then be used.
When a target is detected, sweep the general area with the coil,
taking note of where the strongest signal is received.
By shortening the length of the sweep it should be possible to draw an
imaginary line in the ground where the strongest signal is located.
Line up the target at 90° from the initial direction and repeat
the process. The object is located where the two imaginary lines cross (see
Figure 6.4).
Figure 6.4 Pinpointing technique
NOTE Pinpointing will not locate a target in the centre of
the coil if operating with the Coil switch set to M (Mono) or
Cancel.
44
DETECTING
6
IMAGINARY LINE
OF STRONGEST SIGNAL
SWEEP
DIRECTION
SWEEP COIL AT 90 DEG
TO PREVIOUS SWEEP
EXACT
LOCATION
OF TARGET
P0173-A
TARGET COULD BE
ANYWHERE IN THIS
AREA
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