Vibrating Wire Pressure Cells measure total stresses in soils and is a combination of effective stress and pore-water pressures. They are normally used to validate design assumptions and to give adequate warning of soil pressures in excess of those designed to be exerted by a structure.

VW Pressure Cells are installed within fills to determine the distribution, magnitude and directions of total stresses. They can also be installed with one surface against a structure to measure total stresses acting on retaining walls, against piles, pipes, and slurry trench walls.

Manufactured incorporating Interfels 30 years of expertise in Vibrating Wire instrument technology, the VW Pressure Cell consists of a circular flat cell formed from 2 stainless steel plates welded together around their periphery. The narrow gap between the plates is filled with hydraulic oil and a Vibrating Wire pressure transducer is connected to the cell by a short length of steel tubing forming a closed hydraulic system. The total pressure acting on the surface of the cell is transmitted to the fluid inside the cell and measured by the pressure transducer. Furthermore the cells are fitted with thermistors for correcting the effects of temperature variations on pressure readings.

The pressure cell is embedded in the medium to be monitored and an armoured cable connects the instrument to a terminal unit, portable readout unit or datalogger.