An experimental setup for contactless measurement of the velocity of Rayleigh waves and the surface displacement amplitude

An experimental setup is described on which acoustic pulses were recorded from a small surface area. The setup consists of a contactless electromagnetic-acoustic receiver in which the inductor is two thin straight parallel conductors that are positioned a small distance from each other. The velocity of a Rayleigh wave was determined in the 2–10 MHz frequency range. At these frequencies, the length of a surface acoustic wave was varied from 600 to 240 μm and the minimal spacing for measuring the velocity of the Rayleigh wave at a frequency of 10 MHz was 500 μm. A new method for measurement of the time interval between two acoustic pulses is proposed.