Fig. 2From: Physical property characterization of the Waipapa greywacke: an important geothermal reservoir basement rock in New ZealandA schematic illustration of the sample assembly contained within the pressure vessel used for the experiments described. It also highlights the position of the piezoelectric crystals within the assembly that are used for the P- and S-wave velocity measurements (Faulkner and Armitage 2013)Back to article page