A modified pressure plate apparatus.

Abstract

Soil-water characteristic curves of soils can be measured in the laboratory using conventional testing apparatus such as the pressure plate. This paper describes a modified pressure plate apparatus using a commercially available high air entry ceramic plate. The modified pressure plate apparatus has several advantages over the conventional pressure plate apparatus: It can be used to determine both the drying and wetting soil-water characteristic curves, whereas the conventional pressure plate can usually determine only the drying soil-water characteristic curve; the water reservoir beneath the ceramic plate ensures that the ceramic plate is fully saturated at all times; air appearing in the water reservoir due to air diffusion through the ceramic disk can be flushed out by the cross-flow system during the test without stoppage of the test.