Bendix Autolite Corporation

Other

Tseng Y Tien

James D Bode

Donald C Davis

Donald J Romine

Ching T Young

Phillip R Woodruff

An activated oxygen gas sensor element having an increased voltage output under rich gas conditions, short switching response and reduced internal resistance is produced by chemically treating the inner conductive catalyst electrode of the sensor element with an inorganic acid or acid salt and current activating the outer conductive catalyst electrode by applying a direct current to the sensor element, with the outer electrode as a cathode, while the outer electrode is at an elevated temperature and in the presence of a neutral or inert atmosphere. Air may be used as the atmosphere in contact with the outer electrode during the current activation provided that the sensor is subjected to a subsequent reheating step to provide the desired results.

Process for producing oxygen gas sensor elements

An activated oxygen gas sensor element having an increased voltage output under rich gas conditions, short switching response and reduced internal resistance is produced by chemically treating the inner conductive catalyst electrode of the sensor element with an inorganic acid or acid salt and current activating the outer conductive catalyst electrode by applying a direct current to the sensor element, with the outer electrode as an anode, while the outer electrode is at an elevated temperature and in the presence of a nonoxidizing atmosphere.

Process for producing an activated oxygen gas sensor element

An oxygen gas sensor having a solid electrolyte oxygen gas sensor element, with an inner conductive catalyst electrode on the interior surface and an outer conductive catalyst electrode on the exterior surface thereof, which has a high voltage output and lower internal resistance is produced by chemically activating said inner conductive catalyst electrode with an inorganic acid or an acid salt. By also subjecting said outer conductive catalyst electrode to a direct current activation under a reducing atmosphere, even more improved properties, such as fast switching response, are achieved.

Process for producing improved solid electrolyte oxygen gas sensors

A transducer operative to generate an electrical signal proportional to the partial oxygen pressure in a gas consists of a tube, closed at one end, of zirconia stabilized with yttria. The outer surface of the tube is coated with a porous electronic conductor and a porous platinum layer is coated over the porous conductor so that the platinum contacts the zirconia tubes at the voids in the conductor coating. Electrodes attached to the inner and outer surfaces of the tube sense the potential difference generated across the tube as a result of galvanic action. The open end of the tube is encased within a ceramic cylinder having an outer metal threaded sleeve. Electrodes attached to the inner and outer surfaces of the tube are joined to a connector fixed at the far end of the ceramic tubes. A second embodiment employs a sensor consisting of a transition metal oxide pad and a thermistor pad on a ceramic substrate bonded to a second substrate containing a deposited resistance element so as to hermetically seal the element. The sensor is encased in a ceramic cylinder having an outer metal threaded sleeve.

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Ann Arbor, MI, United States of America

Tseng Y Tien