Volume 1, Issue 4 (December 1978)
Water-Manometer Tensiometers Installed and Read from the Land Surface
Soil-moisture tension has been measured beneath an artificial-recharge basin in Suffolk County, Long Island, N.Y., with water-manometer tensiometers that can be installed and read from the land surface. The manometer-tensiometer unit is buried at the desired depth, and soil-moisture tension is measured from the land surface with a simple wire probe and electrical circuit that detect the level of water in the manometer. The water manometer is more sensitive than other common methods for determining unsaturated pressure head or soil-moisture tension over small ranges and is most helpful in situations where small changes in soil-moisture tension can reflect significant changes in hydraulic conductivity. Although the configuration may not be appropriate for installation at great depth (> 6 m) or in extremely coarse or fine soils, it provides rapid, reliable measurement of soil-moisture tension.