Soil Water Potential Sensors

Water potential describes the force that drives water movement. It is the most fundamental and essential measurement in soil physics. A water potential sensor is a solid-state electrical resistance sensing device that is used to measure soil water tension. As the tension changes with water content the resistance changes as well. That resistance can be measured using a water potential Sensor. The sensor consists of a pair of highly corrosion resistant electrodes. A current is applied to the sensor to obtain a resistance value. The readout unit or datalogger correlates the resistance to centibars (cb) or kilopascals (kPa) of soil water tension.