CHARACTERISTICS OF AN OXYGEN GAUGE AT TEMPERATURES LOWER THAN 200-DEGREES-C

Oxygen gages involving a PbSnF//4 electrolyte were tested at temperatures lower than 200 degree C. The Sn-SnF//2 mixture was used as a reference electrode. Various electrode materials were investigated (metals, oxides with perovskite or rutile structures). The selected electrode material was RuO//2. Doping of the fluoride electrolyte with peroxide ions improves noticeably the performances of the gage (stability of the response, time-lag, etc. ). In the temperature range 150-200 degree C, the response time of the gage is of the order of one minute in the oxygen pressure range 10** minus **3-1 atm.