Soil moisture - capacitance (5TE Decagon)

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Decagon 5 TM.jpg

Contents

Parameter to be measured:

Soil moisture, soil temperature, EC

Method:

Capacitance

Equipment:

  • 5TE Decagon
Effective range of temperature: -40°C - +50°C
Effective range of soil moisture: 0 - 60 % volumetric water content
Accuracy: ±3% without calibration, ±1% - ±2% with calibration
Dimensions: 145mm x 33mm x7 mm, three stripes

Advantages:

  • Relatively cheap
  • Easy to install
  • Compatible with many loggers

Disadvantages:

  • Calibration needed
  • Small measurement volume compared to other sensors
  • not for portable usage designed
  • life time is short (in the first two years errors of the measured values start to increase, especially the temperature sensor is effected)
  • by a combined use with a Campbell Scientivic logger very carefull handling is important, otherwise the probe can be easily blown up

What to watch out for:

  • Careful installation, air gaps have a sustainable influence on the measurement compared to other sensors because of the small measurement volume
  • Probe is fragile and will break if it is pushed into resistive media.

Problems/Questions:

Links

Projects that used the above equipment:

Other related web sites:

References

Rosenbaum, U., Huisman, J.A., Weuthen, A., Vereecken, H., Bogena, H.R. (2010): Sensor-to-Sensor Variability of the ECH2O EC-5, TE, and 5TE Sensors in Dielectric Liquids. VADOSE ZONE JOURNAL, 9(1), 181-186, DOI: 10.2136/vzj2009.0036.
Rosenbaum, U., Huisman, J.A., Vrba, J., Vereecken, H., Bogena, H.R. (2011): Correction of Temperature and Electrical Conductivity Effects on Dielectric Permittivity Measurements with ECH(2)O Sensors. VADOSE ZONE JOURNAL, 10(2), 582-593, DOI: 10.2136/vzj2010.0083.
Rosenbaum, U., Bogena, H., Huisman, J.A., Peterson, T.J., Weuthen, A., Western, A.W., Vereecken, H. (2012): Seasonal and event dynamics of spatial soil moisture patterns at the small catchment scale, WATER RESOURCES RESEARCH 48, W10544, DOI: 10.1029/2011WR011518.
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