p24
8.
2.
Calibration of Meter
Before using the Digital Target Meter, it is necessary to calibrate it as follows:
a)
Set the Calibration control knob (situated to the rear of the meter) to the center position
of its range.
b)
Place the detector in a stationary position with the coil flat on the ground.
c)
Set the Sensitivity control on the Control box to Auto (extreme anti-clockwise).
d)
If the threshold is varying because of electrical interference, adjust Sensitivity clockwise
towards minimum until a constant threshold is present.
e)
Slowly pass a common coin across the coil and finely adjust the Calibration control to
the nearest number, divisible by 5 [e.g. US quarter -set to 170 , AUS 20c - set to 165.]
f)
Slowly pass additional coins and other common targets across the coil and record the
results on the target recognition table shown on page 25.
This table will become an excellent guide when used in conjunction with the Digital Target
Indicator until the various target responses become familiar. This meter should not be
solely relied upon for discrimination. It is important to use the other features of the
Sovereign GT to aid in the process of discrimination.
Be aware that some similar objects may vary in Target Indication readings because of
changes in composition. For example, gold rings will produce different readings
depending upon the purity of the gold and the size of the band. Coins minted in different
years may have different alloy combinations and so the reading will differ. The Target
Indication readings will also be influenced by an object’s orientation, the length of time it
has been buried in the ground and different ground conditions.
www.minelab.com
www.minelab.com
p25
Target Recognition Table
Object Type
Reading
US quarter
non-ferrous
170
AUS 20c
non-ferrous
165
