Discrimination Search Mode And Setup - AKA T72 Operating Manual

Care should be taken when setting the ground balance point either negative or positive. When set
negative it increases the possibility of receiving false positive responses when bumping the coil on
vegetation or the ground. When set positive you risk the chance of losing sensitivity to large silver or
copper coins that will either become "invisible" or ID as iron.
In the event that a "clean" patch of ground is not found you can excavate a small amount of local soil
(1-1.5 kg), removing all metal objects, and place in a bag for convenience. Now lean the detector
with the coil facing up against a bush or tree with the coil at least 40-50cm off the ground. With the
bag of soil in hand you can now and press the GROUND button and count 1,2,3. Then smooth and
slow, (starting from a distance of 30-40 cm) present the soil to coil. (As if doing auto balance on the
ground in the normal mode, but now you are moving the soil to the coil instead of vice versa)
Placing the excavated soil on the ground is not desirable. Since you were not able to perform a
ground balance previously, due to the presence of metal in ground, placing the bag of soil on the
ground may cause an incorrect ground balance.
Attention! If the signal from the ground is too small (such as quartz sand) and the auto balance
cannot be performed then the balancing procedure can be performed either by using a piece of
ferrite or a piece of red brick. These can be placed on the ground and the auto balance procedure
performed. In principle, using the procedure for balancing for "an air test" will also work and you
may set the balance point 1 or 2 degrees negative if you are searching for large objects.
Sharp temperature changes on the search coil may impact balancing accuracy, the balance may shift
and become incorrect with such changes. That is why, if you take the device from a heated car and
start working in a low temperature conditions (early spring, late fall), rebalance one or two times
while the coil adapts to the ambient temperature.
In case of large temperature drops of more, than 15°С (compared to a normal air temp of 20C), we
recommend that you perform electronic module and search coil adaptation procedure one more
time (see Search coil Replacement). In this case the processor of your detector will choose the
optimum frequency of the excitation current for the current temperature conditions. In saltwater
beach operations and other complicated soils with high conductivity we recommend you use the
"Economy Mode" option for better ground balance accuracy.
Sometimes decreasing sensitivity will allow for a more accurate ground balance especially on
beaches. In rare cases, such as after replacement of the coil or attempting to balance on a metal
object, a situation may arise when you cannot perform an automatic ground balance. This occurs
because the current value of the phase vector moves out of the locked system acquisition sheet
(such as a significant change in ambient temperature). You can solve the problem by balancing in
manual mode. To do this, while in the automatic balancing press OK to go to the manual mode and
using the buttons + and - get the vector of the ground signal moving from left to right in strictly the
horizontal direction. After that, the balancing procedure will operate normally.

DISCRIMINATION SEARCH MODE AND SETUP

Discrimination is the ability of the device to respond to certain types of objects and ignore the
others. For example, you can configure the appliance so that it will respond only to objects of non-
ferrous metals while ignoring everything else. In some cases, this allows you to increase the comfort
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