METER GROUP TEROS 12 SOIL MOISTURE SENSOR
Previously known as Decagon Soil Moisture Sensor
The METER Group TEROS 12 sensor measures soil moisture, soil temperature and bulk EC. The sensor has been optimized for use in soilless substrates, leaving it a wider range of bulk EC measurement and an increased temperature range. The steel needles not only slice through the substrates for perfect contact, but also improve the sensor‘s ability to measure bulk EC in porous substrates such as peat or perlite. The sensor also works well in mineral soils. Its 70 MHz frequency minimizes salinity and textural effects, making it accurate in most soil or soilless media. Stainless steel needles have an extended surface area to optimize bulk EC measurements, while minimizing substrate disturbance during insertion.
SENSOR | METER GROUP TEROS 12 SOIL MOISTURE SENSOR |
Part No. | ECH-GS3 |
TECHNICAL SPECIFICATIONS
Volumetric water content (VWC) | Range: Mineral soil calibration: 0.00–0.62 m3/m3; Soilless media calibration: 0.0–1.0 m3/m3; Apparent dielectric permittivity (εa): 1 (air) to 80 (water); NOTE: The VWC range is dependent on the media the sensor is calibrated to. A custom calibration will accommodate the necessary ranges for most substrates. Resolution: 0.001 m3/m3 Accuracy: Generic calibration: ±0.03 m3/m3 (±3.00% VWC) typical in mineral soils that have solution EC <8 dS/m; Medium specific calibration: ±0.01–0.02 m3/m3 (±1–2% VWC) in any porous medium; Apparent dielectric permittivity (εa): 1–40 (soil range) , ±1 εa (unitless) 40–80, 15% of measurement |
Temperature | Range: −40 to 60 °C/br> Resolution: 0.1 °C/br> Accuracy: ±1 °C |
Bulk electrical conductivity (ECb) | Range: 0–10 dS/m (bulk)/br> Resolution: 0.001 dS/m/br> Accuracy: ±5% of measurement |
Dimensions | 9.4 cm (3.70 in) lenght; 2.4 cm (0.95 in) width; 7.5 cm (2.95 in) height |
Prong length | 5 cm (1.97 in) |
Operating temperature range | -40 °C to + 60 °C |
Cable length | 5 m (standard); 75 m (maximum custom cable length) |
Supply voltage (VCC) to GND | 4.0 VDC – 15.00 VDC |
Current drain (while asleep) | Typical: 0.03 mA |
Current drain (during 25-ms measurement) | 3.0 mA – 16.0 mA Typical: 3.6 mA |
Measurement duration | 25 ms – 50 ms |

PESSL INSTRUMENTS GmbH
Werksweg 107, A-8160 Weiz, Austria
Tel: +43 (0) 3172 5521, Fax: +43 (0) 3172 5521 23
E-mail: sales@metos.at, Webpage: www.metos.at