A transmitter coil supplied by an oscillator establishes a magnetic field alternating at 200 kHz in the scanning area. If any conductive metallic particles enter into the magnetic field, an induction current is generated that can then be received in a further coil. Evaluation electronics downstream of this supply a continuous or pulsed signal.
Area of use
Metal detector systems are used on flat, running webs in the textile industry in order to detect metallic particles.
The scanning head can be freely mounted in terms of position. Before and after the scanning head the web should be guided over the metal detector. Here, a small wrapping angle of < 5° should be aimed for. The distance between the guide rollers before and after the scanning head should be at least 500 mm. No strongly magnetizing and rotating steel rollers may be located in this area.