2. Design and method of operation
2
Design and method operation
2.1 Functional
principle
The material to be inspected (bulk or lump material) passes the detector head (2) on a belt conveyor
(1). The lower part of the belt can be put also through the detector head (3).
1
2
3
The material is penetrated within the aperture of the detector head by a high frequency electro-
magnetic field, which is generated by the control unit and the transmitter coil. Two identical voltages
are induced into the receiver coils, and are subtracted to zero if the system is in balance.
1
2
4
E
E
2
2
S
S
E
E
1
1
A metallic impurity (4) causes an unbalanced condition that generates a signal at the receiver. The
control unit processes this signal and triggers an output relay (see operational manual).
7
