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2. Having found the metal-free area, raise the coil 30-40 cm above the
ground press wait for 3 seconds, and move the coil to the
ground smoothly but not too slow.
Warning!
Do not move the coil to the ground closer than 10% of the search
coil diameter (for the search
coil
Ø26 cm – 2-3 cm). This is related to the
change in the pattern of the search coils physical interaction with the
ground in what is called
the “Close Zone” and it may impact balancing
accuracy resulting in false responses in clean areas with high levels of
sensitivity.
If there is no tone or it does not sound during lowering, but sounds
when moving up, repeat the procedure. Follow the ground vector on the
screen during the process. Its shape should be a strait, slightly trem-
bling line, on the horizontal axis of the ground scale. If it makes
sharp angles or is “chaotic” on the screen, this means that you are trying
to balance near a metal object in the ground. In this case, the device
may perform a ground balance, however it will be incorrect and you
will notice multiple false signals from the ground. If this occurs, simply
re-balance the detector in an area clear of any metal
targets
.
Attention!
In automatic balancing mode, do not turn off the device.
Otherwise, the balance data will not be stored in the device memory.
Once
you have chosen a clean location to balance the detector and have done
so, note the value in the lower left hand corner of the ground
balance screen Now, should you cho
o
se to ground balance again later
on and there is a sharp difference between this value now, as compared
to the previous ground balance, there is
a
good reason to suspect that
there was metal close by and you will need to ground balance again. If
the coil all the same was a metal object, giving an automatic balance
(items with VDI close to 0, e.g. foil), the device will give two consecutive
tones, similar in tone to that of iron in the search mode, while at the
same time the screen will display an exclamation point within a
triangle. Accordingly, you will need to ground balance again on a clean
