Tension infiltrometer enhancements with automated pneumatic control and more durable base plate

Measurement of soil hydraulic retention and conduction parameters using tension infiltrometers has been found to be useful but has suffered from unreliable instrument membranes at the soil interface and the need for manual control, which limits the range of boundary conditions that can feasibly be established. An automated design is presented that is capable of maintaining time-varying pressure and flux using high-speed computer-regulated pneumatic valves. Further, a durable stainless steel supply membrane designed to withstand multiple uses under harsh field conditions with bubbling pressure head <−0.60 m H₂O is demonstrated.Keywords: permeability, instrumentation, infiltratio