soil volumetric water content & temperature sensor


METER Group's TEROS-11 soil water content and temperature sensor, formally known as the Decagon 5TM sensor, delivers temperature, measured by an onboard thermistor, along with accurate volumetric water content.

The TEROS-11, which has replaced the older 5TM model, determines volumetric water content (VWC) by measuring the dielectric constant of the soil (or other media) using capacitance/frequency domain technology. Signal filtering minimizes salinity and textural effects, making the TEROS-11 accurate in most soils and soilless media. Factory calibrations are included for mineral soils, potting soils, rockwool, and perlite.

The TEROS-11's small size makes it easy to install in the field and the greenhouse. This robust sensor can be pushed directly into undisturbed soil to ensure good accuracy.


plug and read

Get straight to the data with an ZL6-series data logger. Just install the TEROS-11, plug it into the ZL6, set the clock and measurement intervals, and start logging data. No programming required.

The TEROS-11 comes standard with both serial and SDI-12 communication options, meaning easy integration with systems manufactured by other companies.


advantages of the TEROS-11
  • Measures VWC and temperature
  • SDI-12 compatible
  • 715 mL volume of influence


sensor measurement zone dimensions



whole system monitoring solutions

Sap Flow MeterEdaphic Scientific is a one-stop shop for a whole system monitoring solution. We provide plant and soil monitoring systems for researchers and growers including a LoRa WAN option.

Our systems not only support dendrometers, but related sensors such as sap flow, soil moisture, weather parameters, and more.

At Edaphic Scientific we want to work with you from the start of your project through to its completion. We can provide:

  • Assistance with project and experimental design
  • Procurement of all monitoring equipment, including sensors, data loggers and data management software. Edaphic Scientific is a one-stop shop where we can source and find any necessary equipment for your project from our preferred suppliers or third party suppliers
  • Installation and training
  • On-going assistance with data interpretation and equipment maintenance
  • Data correction and analysis, including statistical analysis with the R-package
  • Report and publication preparation including tables, figures, graphs, and manuscript writing


advanced data collection and management solutions

Edaphic Scientific recognises the need for flexible and adaptable sensor and data logging solutions for experimental or environmental monitoring projects.

Data can be downloaded directly in the field from data loggers. A direct connection between the data loggers and your computer, via a USB cable, can be used for manual downloading of data.

Alternatively, data can be downloaded over the internet on your iPhone, iPad or desktop computer with the Eagle cloud-based, data management software solutions. Through this remote based downloading capabilities, you can download, view and manage your data, and system, anywhere in the world and at anytime.





feature specification
Soil Moisture Apparent Dielectric Permittivity (εa): ± 1 εa from 1 - 40 (soil range); ± 15% from 40 - 80 Soil Volumetric Water Content (VWC): Using Topp equation: ± 0.03 m3/m3 (± 3% VWC) typical in mineral soils that have solution electircal conductivity < 10 dS/m; using medium specific calibration, ± 0.02 m3/m3 (± 2% VWC) in any porous medium
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 from 1-20, < 0.75 εa from 20-80 VWC: 0.0008 m3/m3 (0.08% VWC) from 0 to 50% VWC
Temperature 0.1°C
Soil Moisture εa: 1 (air) to 80 (water) VWC: 0% to saturation
Temperature -40 to 60°C
sensor type
Soil Moisture Frequency domain / capacitance
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, 10 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 10 cm x 3.2 cm x 0.7cm
Data Logger Compatibility Decagon Em50 Series, ProCheck, SDI-12 data loggers
Warranty One year, parts and labor

manual & docs

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