Highlights
- Development of an open-source, low-cost datalogger
- Rugged design for extreme environments
- Successful long-term field validation
- Support for multi-parameter research
Abstract
Carbon dioxide (CO₂) dynamics in caves are critical for karst processes, speleothem growth and dissolution, microclimate regulation, and caver safety. In cave atmospheres, CO₂ commonly derives from soil respiration, epikarst degassing, microbial activity, and, in tectonically active regions, deep-seated fault-related emissions. Fault-related CO₂ degassing may also track tectonic activity. However, continuous monitoring remains limited due to the cost and inflexibility of commercial instruments. Here we present an open-source, low-cost Arduino-based CO₂ datalogger designed for cave applications. The logger integrates a COZIR NDIR CO₂ sensor, a DS1337 real-time clock, microSD storage, and power-gating for extended deployment in humid environments. Firmware and wiring schematics are provided to ensure reproducibility and encourage adoption. The system was deployed in a fault-controlled cave to monitor microclimate and CO₂ variability, providing stable measurements at a fraction of the cost of commercial instruments. By releasing the code and design as open hardware, we aim to broaden access to cave CO₂ monitoring and foster community-driven improvements.
DOI
https://doi.org/10.5038/1827-806X.ijs2571
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.
Recommended Citation
Pennos, C., Christaras, D., 2025. SpeleoCO: an open, low-cost Arduino CO2 datalogger for cave microclimate monitoring. International Journal of Speleology, 54(3), ijs2571. https://doi.org/10.5038/1827-806X.ijs2571
Supplementary
Included in
Environmental Monitoring Commons, Natural Resources and Conservation Commons, Other Oceanography and Atmospheric Sciences and Meteorology Commons, Sustainability Commons
