The Pundit Lab+ Ultrasonic Instrument employs two transducers, one on either side of a solid sample, to emit and receive pulse frequencies. Of a sample of known length, the time from onset to reception can be used to determine the pulse velocity of the P-wave through the sample. The device can also be connected to a laptop so that the waveform response can be viewed allowing for the S wave to be identified also.
The device has two transducers which require slightly different workflows. The 54kHz transducers require the application of standard proceq couplant and are only able to measure the onset of the P-wave. However, they can be used in the field without the assistance of the laptop software. The 250kHz transducers require the application of specialist S-wave couplant (which must be administered at the laboratory) but are able to measure both P and S wave onset times via the laptop software.
With a known density, the P and S wave velocities can be used to determine Poisson's Ratio and the Modulus of Elasticity. These values are essential for understanding the earthquake response of different rock types in the earth's crust.
The Device is currently housed in the Petrophysics Laboratory at University of Melbourne but can be easily transported for use off site.
