Patent ID: 7799203

Claim:
A gas detection apparatus comprising: a gas sensor element which comprises at least one sensor cell including a solid electrolyte member and a pair of electrodes provided on opposite sides of the solid electrolyte member, and a plurality of external connection terminals electrically connected to the respective electrodes of the at least one sensor cell; and a gas-sensor control circuit for controlling the gas sensor element, the gas-sensor control circuit comprising a plurality of control terminals electrically connected to respective external connection terminals of the gas sensor element, an inspection current supply circuit for supplying an inspection current to an inspected terminal, which is a control terminal to be inspected for a presence or absence of a short circuit to a predetermined potential, an inspection potential measurement circuit for measuring the potential of the inspected terminal, and an uninspected terminal impedance increasing circuit for increasing the impedance of the gas-sensor control circuit as viewed from an uninspected terminal, which is a control terminal other than the inspected terminal, to electrically isolate the gas sensor element from the gas-sensor control circuit before the control terminal is inspected for the presence or absence of a short circuit to a predetermined potential.