EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Application of a low-cost NDIR sensor module for measurements of in situ soil CO2 concentration

Adrian Heger1,2, Volker Kleinschmidt1,2, Alexander Gröngröft1,2, Lars Kutzbach1,2, and Annette Eschenbach1,2
Adrian Heger et al.
  • 1Institut für Bodenkunde, Universität Hamburg, Allende-Platz 2, 20146 Hamburg
  • 2Center for Earth System Research and Sustainability, Universität Hamburg, Grindelberg 5, 20144 Hamburg, Germany

We applied the low-cost non-dispersive infrared sensor module K33 (ICB, Senseair, Sweden) for measurements of soil CO2 concentration. We integrated the sensor module in a new soil probe suitable for in situ measurements of soil gas CO2 concentration. Therefore, we covered the sensor module with epoxy resin. For continuous measurements, we connected our soil CO2 probe to a microcontroller (MEGA 2560 Rev3,, Italy) equipped with a data logging shield (Adalogger FeatherWing, Adafruit, USA). In a laboratory experiment, we evaluated the accuracy and precision of our soil CO2 probe at changing temperature and humidity by comparison with the often used CO2 probe GMP343 (Vaisala, Finland) as a reference. In a field experiment, we buried our soil CO2 probe to test its performance under natural environmental conditions.

The result of the laboratory experiment is that our soil CO2 probe compares well with the GMP343, even at maximum relative humidity. The accuracy (<0.1 % CO2) was below the accuracy given by the manufacturer. The field experiment demonstrated that our soil CO2 probe provides high-quality measurements of soil CO2 concentrations under in situ soil conditions. After retrieving it, it still measured with the same accuracy and precision as before.

In summary, we used the sensor module K33 for the first time to measure in situ soil CO2 concentrations by integrating it into a newly developed probe. The cost-efficient availability of our CO2 probe opens up the opportunity to carry out continuous soil CO2 measurements over long time periods with simultaneously high spatial resolution.

How to cite: Heger, A., Kleinschmidt, V., Gröngröft, A., Kutzbach, L., and Eschenbach, A.: Application of a low-cost NDIR sensor module for measurements of in situ soil CO2 concentration, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5819,, 2020

This abstract will not be presented.