Oxygen sensor for industrial air-fuel control - incorporating a protected solid electrolyte disc in a simple ceramic tube mounting to give accurate and consistent results

摘要

An oxygen sensor particularly adapted for use in industrial air/fuel control systems incorporates a disc of solid electrolyte sealed into a recess in one end of a ceramic tube. The tube is sealed and mounted inside a holder assembly which can be screwed into an opening in the wall of a stack so that one face of the disc is exposed to the stack gas while the other is exposed to the ambient air. The electrodes are formed by painting the surfaces of the disc with a platinum paste while stripes of the paste, one on the inside of the tube and the other in a groove on the outside connect the electrodes to separate terminals outside the stack. Ceramic fibre discs are bonded to the disc surfaces and chloroplatinic acid is deposited on the electrode surfaces through the fibre discs. The sensor is simple and uses very few parts and only a small amt. of platinum. Dissimilar material junctions have been eliminated and the sensor is accurate and reproducible. The sensor has a lower operating temp. than other industrial sensors.