Electrochemical gas detection system

Abstract

There is disclosed an electrochemical gas detector system utilizing a polarized gas diffusion sensing electrode which is exposed to a gas mixture containing an electrochemically oxidizable or reducible gas, such as CO, H.sub.2, H.sub.2 S, SO.sub.2, NO, NO.sub.2 and CH.sub.4 which electrode has a suitable catalyst, such as platinum, iridium, ruthenium, gold, etc., as the active element at which the gas is electrochemically oxidized or reduced, a non-polarizable, reversible counter electrode constituted by a suitable redox couple, preferably of the type metal/metal salt, such as Ag/AgCl or metal/metal oxide, such as Hg/HgO, or metal oxide/metal salt, such as PbO.sub.2 /PbSO.sub.4, and a liquid electrolyte body in contact with both electrodes to constitute a complete electrochemical cell. A constant potential difference is applied between the electrodes which biases the sensing electrode to a selected portion of the electrochemical current-voltage curve for oxidation or reduction of the reducible gas. Means are provided for indicating current flowing between the electrodes as a measure of the concentration of the gas at the sensing electrode.

Dependencies are inferred from the claim text.