Device for detecting the passage of objects and/or of persons

摘要

Device for detecting passage over a surface by use of a piezo-electric cable the signals emitted by which are processed by a monitoring device. The piezo-electric cable 4 is included in a mechanical system 3 and buried at a certain depth in the ground. The monitoring device may be a threshold detection device or a signal comparison device. The cable may be used both as detector and radio wave transmitting aerial. <IMAGE>