A direct comparison of amperometric gas sensors with gas-diffusion and ion-exchange membrane based electrodes.

The effect of the nature of the working electrode used in amperometric gas sensors on the performance criteria of sensitivity, detection limit, gas flow rate and humidity dependence was evaluated. The arrangement based on metallized ion-exchange membranes (Nafion) was compared with gas-diffusion electrodes based on porous poly(tetrafluoroethylene) (PTFE) with metallic electrodes deposited on the rear side. Two representative analyte gases were chosen: SO2, which has fast reaction kinetics, and NO, which has slow reaction kinetics.