A portable tensiometer to in situ determine below-grade soil moisture potential of earthen soil includes, a) a body having opposing first and second ends and being adapted for complete insertion into earthen soil below grade; b) a porous material provided at the first body end, the porous material at least in part defining a fluid chamber within the body at the first body end, the fluid chamber being fluidically sealed within the body but for the porous material; c) a degassed liquid received within the fluid chamber; d) a pressure transducer mounted in fluid communication with the fluid chamber; e) the body, pressure transducer and degassed liquid having a combined mass; f) a flexible suspension line connected to the body adjacent the second body end, the flexible line being of sufficient strength to gravitationally freely self suspend the combined mass; and c) the combined mass being sufficient to effectively impart hydraulic communication between below-grade earthen soil contacted by the porous material under the weight of the combined mass. Tensiometers configured to engage the sidewalls of an earthen opening are also disclosed. Methods of taking tensiometric measurements are also disclosed.
CONTRACTUAL ORIGIN OF THE INVENTION
The U.S. Government has rights in this invention disclosed under contract number DE-AC07-76ID01570 between the U.S. Department of Energy and EG&G Idaho, Inc., now contract number DE-AC07-94ID13223 with Lockheed Idaho Technologies Company.