An electrochemical sensor for corrosive gases that contains at least two electrodes is described. The presence of a target corrosive gas results in the formation of metal ions that can be reduced at an electrode producing an electrical current that depends on the instantaneous corrosive gas concentration and deposition of the metal on the electrode. Extension of this deposit to a second electrode through further deposition will result in a short circuit, the longer the time to the short circuit, the lower the cumulative corrosive gas concentration.