New sensing elements based on the delay line principle

A new delay line arrangement based on the characteristics´ modification of the acoustic waves generated and detected by means of magnetostrictive elements (made of Fe-rich amorphous ribbons or thin films) and which propagate along a non magnetostrictive acoustic waveguide is presented. The elastic properties of the acoustic waveguide can be modified by stress and torsion thus resulting in a change of the propagating acoustic signal. The experimental results concerning the tensile stress and torsion influence on the delay line indicate a nonlinear but monotonic response and absence of hysteresis