Three-electrode high-temperature oxygen sensor

Using micro-electronic techniques, a high-temperature oxygen sensor with three electrodes is designed. Yttrium-doped stabilized zirconia is used to make the solid electrolyte and the supporting substrate for the electrodes. A gold resistance thermometer is installed on the sensor to directly monitor the temperature of gas. The platinum film is covered with a porous alumina coating, to reduce the flow effect on the sensor output and prolong the sensor's life. Tests, conducted at 650-900 °C in the mixture of oxygen and nitrogen with the spanning 0-32.7% oxygen concentration, indicate that the sensor is of higher sensitivity, better reproducibility and durability, fast response, but relatively large current outputs are achieved simultaneously. The sensor fabricated using photolithographic reduction and thick-film metallization techniques is conductive to substantial miniaturization.