5.5 Electrochemical Gas Sensors
Electrochemical gas sensors are gas detectors that measure the concentration of a
target gas by oxidizing or reducing the target gas at an electrode and measuring the
resulting current. The target gas being measured diffuses into the cell through the
diffusion barrier (capillary) and filters. When it comes into contact with the sensing
electrode, the target gas present in the sample undergoes an electrochemical reaction
(oxidation and reduction). The generated electrons from the electrochemical reaction
charge the sensing electrode resulting in current generation.