An electrochemical gas sensor is described incorporating a sensing electrode, a reference electrode, a solid matrix containing an alkali salt, a potentiostat and a heater. The invention overcomes the problem of a liquid electrolyte which may operate over limited environmental conditions....http://www.google.com/patents/US4744954?utm_source=gb-gplus-sharePatent US4744954 - Amperometric gas sensor containing a solid electrolyte
