Low cost CO₂ sensing: A simple microcontroller approach with calibration and field use.

Area of Science:

• Environmental Science
• Sensor Technology
• Ecosystem Monitoring

Background:

• Assessing landscape-scale gaseous carbon flux demands intensive, costly monitoring.
• Existing commercial CO2 sensors often provide inadequate data for large-scale research.
• Significant financial investment is a barrier to comprehensive environmental monitoring.

Purpose of the Study:

• To present designs for a low-cost, microcontroller-based gaseous carbon dioxide (CO2) data logger.
• To enable scalable field deployment for accurate CO2 concentration monitoring.
• To overcome limitations of expensive, proprietary equipment in environmental research.

Main Methods:

• Developed fully replicable designs for a microcontroller-based CO2 data logger.
• Ensured the sensor is low-cost (approx. £155), battery or USB powered, and user-assemblable.
• Validated post-calibration accuracy (96-99%) and onboard data storage capacity.

Main Results:

• The data logger achieved 96-99% post-calibration accuracy.
• It features large onboard data storage for user-defined sampling intervals.
• The sensor was successfully deployed to measure CO2 evasion from a peatland stream.

Conclusions:

• Low-cost, open-source sensors can significantly advance environmental research capabilities.
• This data logger design facilitates previously unanswerable questions regarding carbon processing.
• The design is adaptable for diverse research applications beyond peatland carbon flux.