Bench mark system using elastic surface waves - comprises substrate on which waves are propagated in perpendicular directions to be picked up by transducer probe

摘要

The benchmark system is based on surface elastic waves. It includes a substrate (2) which propagates these waves. An electrical pulse excitation system (6) is connected to an electromechanical transducer (4, 5) which, in turn, is coupled to the substrate (2). A probe (7) with point (8) and a chronometer system connected to the pulse excitation system and to the probe complete the system. The substrate itself comprises a plate having one or more thin crystalline sheets. The surface waves have rectilinear waver fronts and propagate on the surface of the crystal in two distinct directions so that the vibratory energy propagates in a direction perpendicular to the wave fronts.