Connecting Headphones; Basic Adjustment - Monacor GMD-20 Mode D'emploi

it lights permanently during normal operation, the bat-
GB
teries should be replaced.
Dead batteries or defective rechargeable
batteries do not belong in the household
rubbish; always take them to a special
waste disposal (e. g. collecting container
at your retailer).

4.4 Connecting headphones

The output jack (11) allows connection of stereo head-
phones or earphones with a 3.5 mm plug. In this case,
the speaker (9) will be switched off. By using head-
phones during operation of the unit, you will be able to
concentrate better on the search. Besides, the bat-
teries will last longer as the headphones require a
lower output power.
CAUTION:
Never adjust a very high volume when using head-
phones. Permanent high volumes may damage your
hearing! The human ear will get accustomed to high
volumes which do not seem to be that high after
some time. Therefore, do not further increase a high
volume after getting used to it.
Traffic safety: Never use headphones in areas of high
traffic density. When using headphones which also
allow perception of outside noise, only adjust the
volume to such a level that the ambient noise is still
audible.
5 Searching Metal Objects
Prior to using the unit for searching metal objects in
unknown areas, make yourself thoroughly familiar with
the unit. Test it with various familiar objects of different
metals and observe the unit's response to them.

5.1 Basic adjustment

1) Set the switch (2) to the position VLF.
2) Turn the control VOLUME (8) clockwise to approx.
1 / from the left stop.
3
3) Set the controls GROUND (3), SENSITIVITY (5),
and DISCRIMINATION (6) to mid-position.
4) Hold the unit with the search coil above the area to
be searched. The distance from the ground should
be approx. 30 cm and there must be no metal objects
at a distance of less than 30 cm from the search coil.
5) Keep the reference button (10) pressed and adjust
the control TUNING (7) in such a way that the point-
er of the indicating instrument (1) is at "0". Then re-
lease the button.
6) To reset the pointer to "0" while searching in a dif-
ferent environment, shortly press the reference but-
ton once again.
8
5.2 Searching
1) Select the desired operating mode with the switch
MODE:
VLF: searching without distinction between metals
TR1 and TR2: distinction between ferrous and non-
ferrous metals; TR2 even allows a finer distinction
between various non-ferrous metals
If the pointer of the indicating instrument (1) is no
longer in the centre after switching to another oper-
ating mode, hold the search coil at a distance of
approx. 30 cm above the ground and shortly press
the reference button (10).
2) Slowly sweep the search coil at a distance of
approx. 2 – 3 cm above the ground while always
keeping it parallel to the ground. (Never swing the
search coil above the ground in a pendulum move-
ment.)
3) If the unit detects a metal object, the position of the
pointer in the indicating instrument (1) will change.
With non-ferrous objects, the pointer will deflect to
the right and an audio signal will sound. The further
the pointer deflects to the right, the higher the
sound (in three steps). Adjust the volume of the
audio signal with the control VOLUME (8).
In the operating modes TR1 and TR2, the pointer
will deflect to the left when ferrous metals are
detected. In the operating mode VLF, the pointer
will also deflect to the right when ferrous metals are
detected.
The degree of deflection depends on various fac-
tors: the type of metal, the content of metal, the
depth of the object, and the angle of the object to
the search coil.
4) After operation, always switch off the unit to prevent
unnecessary consumption of the batteries: Set the
function switch (2) to the position OFF.
If the unit is not used for a longer period, the bat-
teries should be removed to prevent damage to the
unit in case of battery leakage.
Notes
– For covering the whole area when searching, slow-
ly move the search coil above the ground in par-
allel, overlapping sweeps. If you wish to be on the
safe side, search the same area once again with
sweeps turned by 90°.
– Do not test the unit on the floor of a building. Most
floors contain metal components which may inter-
fere with the measuring results.
Within buildings, the unit may alternatively be
tested e. g. on a table made of wood or plastic.