A comparison of current dissolved carbon dioxide measurement methods with Non-Dispersive Infrared (NDIR) Sensor alternatives.
Water-impermeable non-dispersive infrared (NDIR) sensors were deployed in the field in Brazil, Sweden, Canada, Finland and Scotland, all of which varied greatly in their temperature, hydrology, and biological processes (tropical stormflow, groundwater, cold spring runoff, and wetland beaver ponds).
When compared with the widely-used headspace equilibration method, the NDIR sensors had the advantage of showing finer-scale temporal changes in CO2 concentrations, were less labour-intensive, and were successfully used in soils, and in both well-mixed and poorly-mixed water columns. Johnson et al. (2010) illustrate the advantages of using NDIR sensors in their paper by providing a wide range of in situ, high resolution data.
Johnson et al. (2010), “Direct and continuous measurement of dissolved carbon dioxide in freshwater aquatic systems — method and applications”