Installation for monitoring a rolled-out wire coil

摘要

The invention relates to an installation for monitoring a rolled-out, approximately cylindrical wire coil and its surrounding, by means of a transmitter for electromagnetic waves, a receiver, an evaluation apparatus and an alarm device, the transmitter (2) and the receiver (3) being positioned at the same end face of the wire coil (1), the frequency of the transmitter (2) being sufficiently high for the radiated waves to propagate inside the wire coil (1) in the axial direction, that end face of the wire coil (1) lying opposite the transmitter (2) and receiver (3) being open or screened towards the outside, the transmitter (2) radiating pulse-shaped, preferably square-wave amplitude-modulated waves, the receiver (3) feeding the field strength of the waves to the evaluation apparatus (4) in the form of electric signals, the evaluation apparatus (4) storing the signals, measured in the case of an undisturbed wire coil (1), or their amplitudes and the evaluation apparatus (4) displaying the difference between the received and the stored signals or amplitudes as a function of time and/or actuating the alarm device (5) in case the difference overshoots a predetermined threshold value. <IMAGE>