Hydraulic pressure cells are designed to measure stress in mass concrete or placed at the interface between the structure and the wall of excavation.
The pressure pad consists of two steel plates welded together around their periphery and spaced apart by a narrow cavity saturated under vacuum with de-aired oil which guarantee maximum rigidity. A length of high-pressure rilsan tubing connects the cavity of the pressure pad to the pressure transducer.
A repressurizing device is available for expanding the cell after the concrete has cured. Readings are obtained with portable readout units or dataloggers.