Decagon GS3 Sensor

– soil moisture, temperature and EC sensor

Soil EC SensorThe GS3 soil moisture, temperature, and EC sensor is built with an epoxy body and stainless steel needles. The internal circuitry is the same cutting edge design that you’ll find in other Decagon soil moisture sensors, but the form factor has been optimized for use in soilless substrates or harsh environments, giving it a wider range of EC measurement and an increased temperature range. Not only do the steel needles improve sensor contact, but they also improve the sensor’s ability to measure EC in porous substrates such as peat or perlite.


accuracy at a fraction of the cost

The GS3 measures water content, temperature, and EC independently. 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 EC measurements, while minimizing substrate disturbance during insertion. Temperature is measured with an onboard thermistor, and electrical conductivity is measured using a stainless steel electrode array.


GS3 Measurements


understand your measurements

When used with our DataTrac 3 software, your GS3 data can be used to determine plant available water, growing degree days, and pore water electrical conductivity.


easy integration

Each GS3 comes standard with both serial and SDI-12 communication options, meaning easy integration with systems manufactured by other companies.


Em50 Data Loggeradvantages of the GS3
  • Measure VWC, EC, and temperature in soilless substrates or harsh environments
  • Manage salts
  • SDI-12 compatible


related products


feature specification
Soil Moisture Apparent Dielectric Permittivity (εa): ± 1 εa (unitless) from 1 - 40 (soil range), ± 15% from 40 - 80 Soil Volumetric Water Content (VWC): Using a generic calibration: ± 0.03 m3/m3 (± 3% VWC) typical in mineral soils that have solution electrical conductivity < 10 dS/m; using medium specific calibration, ± 0.01 - 0.02 m3/m3 (± 1 - 2% VWC) in any porous medium
EC ± 5% from 0 to 5 dS/m, ± 10% from 5-23 dS/m
Temperature Temperature: ± 1°C Note: Temperature measurement may not be accurate if sensor is not fully immersed in the medium of interest, due to excessively long equilibration time.
Soil Moisture εa: 0.1 εa (unitless) from 1 - 20, < 0.75 εa (unitless) from 20 - 80 VWC: 0.002 m3/m3 (0.2% VWC) from 0 to 40% VWC, 0.001 m3/m3 (0.1% VWC) > 40% VWC
EC 0.001 dS/m from 0 to 23 dS/m
Temperature 0.1°C
Soil Moisture εa: 1 (air) to 80 (water) VWC: 0% to saturation
EC 0 - 25 dS/m (bulk EC)
Temperature -40 to 60°C
sensor type
Soil Moisture Frequency domain / capacitance
EC Two probe design
Temperature Thermistor
Measurement Speed 150 ms (milliseconds)
Output SDI-12
Operating Environment -40°C to 60°C
Power Requirements 3.6 - 15 VDC, 0.3 mA quiescent, 25 mA during 150 ms measurement
Cable Length Sensors come standard with 5 m cable. Custom cable lengths available. Maximum cable length of 75 m.
Cable Connectors 3.5 mm "stereo" plug, or stripped and tinned lead wires (3)
Sensor Size 9.3 cm x 2.4 cm x 6.5 cm
Data Logger Compatibility Decagon Em50 Series, ProCheck, SDI-12 data loggers
Warranty One year, parts and labor