Application of a Low-Cost NDIR Sensor Module for Continuous Measurements of in Situ Soil CO2 Concentration

We tested the performance of a newly developed CO(2)probe, K33SOIL [based on the sensor module K33 (Senseair, Sweden)], under harsh temperature and humidity conditions in a laboratory experiment. The K33SOIL, competed well (RMSE = 0.032% CO2) with the often used GMP343 (Vaisala, Finland) in precision and accuracy. A field experiment showed that the K33SOIL is also suitable forin situapplications. Thus, the K33SOIL is a valuable and cost-efficient tool for measurement of soil CO(2)concentration.