New technologies integrate to boost sensor performance and banish common sensor installation errors.
PULLMAN, Wash. (May 2, 2018)— METER Group announced the release of its TEROS 12 soil moisture sensor, which uses high-frequency (70 Mhz) capacitance technology to accurately measure volumetric water content, temperature, and electrical conductivity in soil.
Accurately understanding the percentage of water in a soil has traditionally been a complex, costly, and laborious process. Soil moisture is highly variable over short distances, at different depths in the soil profile, and in different soil types and densities. In order to characterize this variability, researchers have to install large numbers of soil moisture sensors into small boreholes or trenches. This is painstaking and tedious—and problematic if the sensors are costly and complex or if the readings vary from sensor to sensor.
Existing soil moisture sensors typically force researchers to choose accuracy and reliability or affordability and simplicity. Technological advancements in the new TEROS 12 soil moisture sensor eliminate this problem by improving all aspects of sensor performance while reducing complexity and cost. Dr. Colin Campbell, Vice President of METER Environment, explained that the goal with the TEROS 12 was to simplify the research process. “Everybody is excited about this new soil moisture sensor. It has all the features a researcher might need at a price that lets them completely characterize their research site. There’s no need to compromise between performance and price.”
The difference comes down to a highly effective precision calibration procedure which maximizes accuracy and minimizes sensor-to-sensor variability (less than 1%), while keeping the TEROS 12 cost reasonable. In addition, the TEROS 12 delivers an impressive 1-liter volume of influence (versus the 200 mL typical for most sensors), which helps smooth variability. The TEROS 12 also boasts improved robustness and reliability. Stainless steel needles and a durable epoxy fill means it lasts up to 10 years in the field.
The TEROS 12’s effectiveness is enhanced by a newly designed accessory: the TEROS Borehole Installation Tool, which enables faster, more accurate, and consistent water content sensor installation. Since only a small 4-inch diameter hand-augered hole is needed instead of a large trench, you can perform a deeper down-hole installation with little site disturbance and far less effort. Because it uses mechanical leverage instead of hand application, sensors are applied straight in and perpendicular with uniform pressure (even through hard clay soils) and then gently released to prevent air gaps, resulting in clean installations. This allows researchers to measure soil moisture in profile without the preferential flow issues that plague traditional profile sensors.
“The installation tool is a significant contributor to the advantages of this sensor,” said Leo Rivera, a METER research scientist on the TEROS development team. “We’re used to focusing on tech when we talk about upgrades, but poor installation can defeat any number of technological improvements. The TEROS 12 produces some of the best soil moisture data we’ve seen, due in part to the innovations built into the installation tool.”
For more information about the TEROS 12, please visit: https://www.metergroup.com/environment/products/teros-12/.