CO2 MONITORING BY SOLID-STATE LIMITING-CURRENT SENSORS

The aim of this contribution is to present some results on CO2 determi nation in N-2/CO2 gas mixtures. The sensor under investigation is a zi rconia (solid-electrolyte) electrolysis cell operating in a limiting-c urrent mode. The diffusion of the gaseous species to the reduction ele ctrode is limited by a pinhole in a pellet sealed to the cathodic side of the cell. The experiments are carried out as a function of CO2 con centration and temperature. It is found that the limiting current depe nds on the CO2 partial pressure, as theoretically predicted. The possi bility of determining CO2 in nitrogen in a wide range of concentration s is confirmed.