F3 COMPACT Service Manual
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8
•
Within two seconds the threshold tone should return to its correct level
f.
Ground Balance Test.
This test confirms the F3 COMPACT is capable of ground balancing
against mineralised ground. In doing so, it confirms the correct operation of the ground balance
button, coil and associated circuitry. The test is conducted as follows:
•
Ensure hands and arms are free of metallic objects (watches, rings etc) and that no other
metallic objects are near the coil.
•
Keep the detector stationary and away from ground or metal objects, press and hold the
ground balance button for five seconds then release the button.
Note
This action will cause the F3 COMPACT to delete the previously stored ground balance condition.
Unless this is done the detector will remember its last ground balance condition regardless of the
unit being switched off or the batteries removed.
•
Slowly move the ground balance test piece from approximately 150mm (6in) above the
coil towards the centre of the coil and confirm that a rise in threshold tone occurs. This
confirms that the detector is detecting the mineralised content of the ground balance
test piece.
•
Press down and hold the ground balance button whilst slowly moving the ground balance
test piece from approximately 150mm (6in) above the coil towards the centre of the coil
(and touching the coil). Then, move the ground balance test piece away from the centre
of the coil to a distance of 150mm (6in).
•
Repeat this process until the ‘Ground Balance OK’ tone consisting of a short high-pitched
double beep occurs. This tone confirms the ground balance procedure has been
completed correctly.
•
Release the ground balance button and confirm that a steady low volume threshold tone
remains.
Figure 5: Audio Reset
