I'm conducting ultrasound experiments on rock samples. In order to numerically model the wave propagation I need to know the actual particle displacements caused by the ultrasound waves. For example, does a negative or a positive voltage pulse correspond to a compressive or a tensile wave pulse? I also would need to know what displacement amplitudes the ultrasound waves have - some way to calibrate the displacement in micrometer with the voltage amplitude measured. Anyone some ideas on this?