UNISCAN is a selective eddy-current metal detector with compensated eddy-
current converter. Signal of metal objects' detection is produced by sending a
signal to the built-in piezoelectric transducer and the LED indicator. The device is
also equipped with LED automatic monitoring of battery discharge. When
discharge level is below (7,2) V, the detector starts producing intermittent light
and sound signals.
In case of detecting a ferromagnetic object (e.g., a Makarov gun), the device
produces monotonous signal of 2-3 kHz frequency. In case of detecting a non-
ferrous metal object (aluminum, copper, gold, etc.), light and sound indication is
intermittent (nightingale trill).
The detector does not distinguish objects with large contours of eddy currents
according to metal grades, i.e. bulky items (pit covers, network of reinforced
concrete structures, body armor). However, these items are identified by the user
according to the detection range. In this case, this value can be up to 80 cm. The
device has a dynamic operation mode, i.e. metal object is detected when moving
the detector over this object.
UNISCAN has the following controls (Figure 1) and indication:
- Power Switch
- Operation Sensitivity Control
- LED Power Indicator
- LED Indicator of metal objects
- Toggle Switch to disable indication of non-ferrous metals
4. PREPARATION AND OPERATION ORDER
Remove battery compartment cover and install the battery. Turn on the
device. This should be followed by a sound signal and the LED power indicator
lights up. By rotating the knob of operation sensitivity control, set the desired value
of this parameter, bringing to the indicator this or that metal object (watch, coin).
Recommended scanning speed while inspection is about 0.5 m/s. During
inspection in order to identify firearms, do not hold the device too close to the
inspected person. Recommended distance is 15- 25cm. This is because a human
body has low electrical conductivity, to which the detector may react. In addition,
in order to avoid false alarms it is necessary that the inspection area within a radius
of 1,5-2 m is free of large metal objects (turnstiles, safes, reinforced concrete
structures).
5. HOW TO MAKE USE OF SELECTIVE PROPERTIES OF THE DEVICE
The nature of electromagnetic interaction of the device sensor and a metal object is
very complicated. In practice, this may lead to some ambiguities in determining the
type of object material. Example. If you take a steel sheet size of 200x200 mm, and
bring it down flat to the sensor device, the latter will react with 'nightingale trill',
