Oscillatory-mode oxygen sensor

A high-temperature (∼ 800°C) O2sensor is described based on O2pumping and sensing with ZrO2, O2-concentration cells. The cells are incorporated in a ceramic structure that defines an enclosed volume which communicates with a gaseous ambient of interest by means of a small leak. An oscillatory pumping procedure is described whose period is proportional to at least the first power of the desired ambient O2-partial pressure over a substantial pressure range. The device has potential application for monitoring engine air-to-fuel ratio based on the O2content of exhaust gas.