Calibration-free optical chemical sensors

Calibration-free optical chemical sensors are feasible, as gleaned from sensor intercomparisons and long-term studies of the sensor response. A reagent-based optical chemical sensor has been developed for autonomous mooring-based measurements of seawater pCO2. The sensor demonstrates excellent sensor-to-sensor reproducibility and long-term measurement stability. These show that such sensors could circumvent the need for periodic calibrations.