A flexible sonic probe extensometer that allows detailed measurement of ground movement in mine and tunnel excavations, the ETM-X is highly accurate (+/-0.5mm) and can measure up to 20 anchor positions along a 7m long borehole.
Each system consists of a flexible probe and transducer head, which is connected via a cable to a portable rechargeable CANbus readout unit with high visibility LCD screen. A single system can be used to measure strata movement at multiple locations in a mine or tunnel system as the probe is only inserted into the borehole when a reading is to be taken.
Readings can be stored for download to a PC to allow trend analysis and compliance reporting.
Measure dilation of strata throughout the length of a 7m hole
Identifies the horizons where dilation occurs
Determines the height of failure or roof softening
Demonstrates trends of strata deformation