Soil - Water Potential

Soil Water Potential Sensor - TEROS 22

With the same high accuracy and low maintenance you’ve come to expect and trust from METER. Over 40 years of experience has brought us to the next evolution of simple and precise water potential measurements — Introducing the TEROS 22

The TEROS 22 is designed to be a maintenance-free matric potential sensor for long-term, continuous field measurements. The TEROS 22 measures the dielectric permittivity of a solid matrix to determine the water content of the solid matrix. The relationship between water content and matric potential, known as the soil moisture characteristic curve, is used to calculate the soil matric potential of the solid matrix. This measurement approach along with the calibration process used in production allows for accurate measurements of water potential.

  • Easy to install and remove
  • Install via 16 mm (5/8 in) drill hole or in the side of a trench
  • Tough, long-lasting body
  • No recalibration needed
  • Low salt sensitivity
  • Affordable
  • Excellent range (sensitivity from 0 kPa all the way to air dry [-100,000 kPa])
  • Onboard temperature measurement
  • Plug-and-play capability
  • Use with the ZL6 data logger for remote access to data on the cloud
  • DDI Serial and SDI-12 compatible 

Water Potential

  • Range −5 to −100,000 kPa (1.70 to 6.00 pF)
  • Resolution 0.1 kPa
  • Accuracy ±(10% of reading + 2 kPa) from −5 to −100 kPa


  • Range −40 to +60 °C
  • Resolution 0.1 °C
  • Accuracy ±1 °C

The SDI-12 sensor communication configuration.

  • Baud Rate 1,200
  • Start Bits 1
  • Data Bits 7 (LSB first)
  • Parity Bits 1 (even)
  • Stop Bits 1
  • Logic Inverted (active low)

 •  Deficit irrigation monitoring and control
 •  Water potential monitoring in the vadose zone
 •  Crop stress
 •  Waste water drainage studies
 •  Plant water availability

Continuous monitoring with seasonal flexibility

Choose an instrument that conforms to your installation needs instead of compromising your research. While trenching at installation and removal works for some, it is limiting for research areas such as agricultural environments and geotechnical engineering projects. That’s why the TEROS 22 is designed with the flexibility to be installed with a drill-mounted masonry bit or the traditional trenching method, making water potential measurements available to just about any application. Keep the sensor in place for years at time for continuous monitoring or remove seasonally, giving you the flexibility to adapt to changing plans and work around seasonal agricultural schedules.

A true full-range water potential sensor that’s low maintenance and low cost

The TEROS 22 water potential sensor is incredibly easy to use. It requires no maintenance, and it’s accurate enough for most applications. In fact, the TEROS 22 provides an even more accurate soil moisture picture than measuring water content alone. Plus, unlike water content, matric potential isn’t dependent on soil type, so you can compare moisture between different sites. Just like the TEROS 21, the TEROS 22 is surprisingly affordable and measures all the way from near saturation to air dry (0 to −100,000 kPa) making them both true full range water potential sensors.

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