A two cell tensiometer is described in which water level in the lower cell is maintained at a relatively constant height, and in equilibrium with the water pressure of materials that surround the tensiometer. An isolated volume of air in the lower cell changes pressure proportionately to the changing water pressure of the materials that surround the tensiometer. The air pressure is measured remotely. The tensiometer can be used in drying as well as wetting cycles above and below the water table.
This invention was made with U.S. Government support under Contract No. DE-AC03-76SF00098 between the U.S. Department of Energy and the University of California for the operation of Lawrence Berkeley National Laboratory. The U.S. Government may have certain rights in this invention.