When it comes to measuring water potential (or soil suction), it's hard to find a sensor that meets your every need. You're either forced to deal with lowered accuracy or high-maintenance hassles (plus getting soaked on cost). That's why we invented TEROS 21.
To say TEROS 21 is more accurate than competitor sensors doesn't do it justice. That's because unlike competitor models, we calibrate each and every sensor for you. To do this, we use a chamber system that allows the TEROS 21 water potential sensor to come to a fixed water potential. We put sensors in silica flour, and by controlling the water potential, we're able to set calibration points from -10 ka to -80 kPa. The result: a long-term monitoring solution you can finally trust.
The TEROS 21 water potential sensor is incredibly easy to use. It requires no maintenance, and it's accurate enough for most applications. In fact, the TEROS 21 provides an even more accurate soil moisture picture than measuring water content alone. A water content sensor only shows the percentage of water in the soil, but add a TEROS 21 water potential sensor, and you'll know if that water is available to plants and where it will move. Plus, unlike water content, matric potential isn't dependent on soil type, so you can compare moisture between different sites. Not only that, the TEROS 21 is surprisingly affordable, and the new Gen 2 version boasts an improved circuit, a more robust microprocessor, and an improved measurement range. It now measures all the way from near saturation to air dry (0 to -100,000 kPa) making it the world's first true full range water potential sensor.