TPC-4000 series Total Earth Pressure cells are designed to measure total pressure (effective stress and pore water pressure) in soils and at the interface between structures and the wall of excavation. They are constructed from two stainless steel plates, welded around their periphery with the narrow gap between the plates filled with hydraulic fluid.

External pressure on the outside surfaces of the cell squeezes the two plates together creating an internal fluid pressure. A length of stainless steel tube connects the cell to a pressure transducer which converts the fluid pressure into an electrical signal which can be directly readout or transmitted to a data logging system.