Weighing Lysimeters for Long‐Term Water Balance Investigations at Remote Sites

Two weighing lysimeters were installed at a remote location on the Dep. of Energy's Hanford Site in Washington State in 1978 and 1979. Platform‐type electronic scales were placed below the soil surface to measure the weight changes of a large (∼7 Mg) container of soil. The load cells of the scales have been exposed to high humidity and to periodic contact with drainage water, but have operated without failure since installation (over 5 years). Weight changes are continuously recorded, with hourly averages transmitted by phone line directly to the laboratory. The sensitivity of the scale is 50 g, equivalent to 0.02 mm of H 2 O.