An innovative multiple extensometer for various applications in tunnelling

Principle of operation

The measurement itself is carried out by pushing the flexible magnetostrictive probe into the guide tube, passing all the anchor parts through their centre hole. When all the monitoring points are lined up along the probe, the readout unit stimulates the ferromagnetic waveguide of the probe which generates microscopic distortions of the molecular structure of the waveguide at the location of the measuring anchors, and respectively their magnetic fields (Wiedemann Effect). The generated torsion waves travel along the waveguide and are detected by a sensor in the measuring head. Expressed in a simple way – the time interval from applying a current pulse until the appearance of the torsion pulse in the measuring head is measured. By knowing the transfer speed of the waveguide and the time intervals, the
distances between the measuring head and the anchor parts are calculated.

Our services

We deliver all components in the desired design. Our technicians are also happy to carry out the installation on site. If an automatic measurement data acquisition is desired, we plan and deliver optimized solutions and accompany our customers until commissioning.