SOLID-STATE GAS SENSOR

摘要

A solid-state sensor (50) provides for sensitive detection of a selected gas in a gaseous mixture to output a signal useful for monitoring and control. The sensor has a solid-state oxide electrolyte (54), a first electrode (52) contacting the electrolyte for oxidizing or reducing the selected gas in the gaseous mixture at a first reaction rate, and a second electrode (56) contacting the electrolyte for reducing oxygen in the gaseous mixture at a second reaction rate. The difference in the first and second rates produces a measurable electrochemical potential across the electrolyte. The improvement in the sensor comprises the first electrode formed from a dense thin film of a mixed conductor suitable for catalyzing the oxidation or reduction of the selected gas. Suitable mixed conductor films are formed from perovskite-type and fluorite-type oxides with a thickness less than about 1 um.