F3 COMPACT Service Manual
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9
•
Confirm the ground balance is correct by moving the ground balance test piece from
approximately 150mm (6in) above the coil towards the centre of the coil. If there is no
alarm from the ground balance test piece the ground balance procedure is functional.
Note
Where the ground balance test is conducted using local soil Figure 6 illustrates the procedure to
be followed.
Note
Successful ground balancing occurs within 5 to 10 seconds. Where the ground balance test piece
or local ground conditions are not sufficiently mineralised the ‘Ground Balance OK’ tones may
take up to 25 seconds to complete.
g.
Earset Test.
This test confirms the earset is operating correctly and is conducted as
follows:
•
Plug the earset into the detector as shown in Figure 7.
•
Switch on the detector and confirm the threshold tone is audible using the earset.
•
If an earset speaker On (4523-0027) is being tested check that the tones can also be
heard from the detector loudspeaker.
•
If an earset speaker Off (4523-0025), identified by green band on the earset cable near
the plug, is being tested check that tones can only be heard in the earset and not the
detector loudspeaker.
Figure 6: Ground Balance
