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Departement of international trade:
of targets certain difficulties arise.
This is due to the very narrow difference between the vector angle of
these targets and those of the ground signal.
This useful component of the vector is the projection of AB to the ver-
tical Y axis. The smaller the angle difference between the ground signal
vector and the vector of the coin the less useful part of the projection
of the signal and the less sensitivity. More important is the fact that the
angular difference becomes even less with the so-called “hot-stone” (see
fig. 26).
In these cases, even a minor incorrect setting of the ground balance can
lead to a significant loss of sensitivity to the large copper/silver coins or
an undesirable (annoying) response to “hot rocks” if the algorithm DHR
is not used.
Note that when setting the ground balance, such as on loam, the angular
difference between the signal and the signal of large copper/silver coins
is about 7-8 degrees. At the same time, the angular difference between
hot rocks is only 4-5 degrees which leads to difficulties in the identifica-
tion of such targets.
In view of the above, it is possible to give some practical recommenda-
tions.
1. As accurately as possible carry out Ground Balance.
2. In areas with little to no metal trash use the AGT.
3. In the presence of hot stones, when not using the DHR algorithm,
carefully open up the right border of the sector discrimination to mini-
mize the risk of missing these types of coins.
Try to adjust the vector phase of the soil by 2-3 degrees in the
