Oxygen sensor with solid electrolyte

The invention concerns a solid-state oxygen sensor in the form of an electrolytic cell with a first electrode exposed to the atmosphere containing the oxygen whose partial pressure is to be measured, a second electrode exposed to a reference atmosphere, and a solid electrolyte in surface contact with both electrodes. The electrolyte material is a ceramic oxide or glassy phase exhibiting pure ionic conduction, and at least the first electrode contains a non-stoichiometric ceramic oxide. The invention calls for the first electrode to be made of a mixture of at least one non-stoichiometric ceramic oxide and a metal, the latter being gold, platinum, nickel or chromium. A sensor of this kind can determine the oxygen partial pressure over a wide range of pressures and is sensitive to poisoning of the electrodes by carbon monoxide or lead.