The PROBEX Borehole Dilatometer is a radially expandable borehole probe used to determine, in-situ, the modulus of elasticity of soft and moderately hard rocks. Tests run with the PROBEX Rock Pressuremeter can reach working pressures of 30,000 kPa. The probe is inflated hydraulically by means of a two-way ram, and deformation readings are obtained by monitoring the displacement of the twin pistons.
