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.
WATERMARK® sensor
- 0-200 Centibar range
- Stainless steel enclosure
- Fully solid state
- Will not dissolve in soil
- Not affected by freezing temperatures
- Internal compensation for commonly found salinity levels
- Inexpensive
- Easy to use
- No maintenance
MPS-6 / Teros 21 Calibrated Water Potential Sensor
- Water potential range -9 to -100,000 kPa
- Accuracy (10% + 2 kPa)
- No refilling or field maintenance necessary
- Plug and play with Decagon data loggers, digital output SDI-12 for non-Decagon data loggers