A LEAKAGE-TOLERANT ZIRCONIA PUMP-GAUGE OXYGEN SENSOR

The operation of a leaky zirconia oxygen pump-gauge is discussed in wh ich the pump was driven so as to generate a sinusoidal EMF at the gaug e of predetermined frequency and amplitude. A theoretical equation for the current is derived and checked for conformance with sensor charac teristics. In general there was good agreement with theory; there was some discrepancy with variation in total gas pressure. It is shown tha t the output current l(0) at zero gauge EMF was independent of the deg ree of leakage while the current l(pi/2) at the gauge EMF maximum was directly proportional to the degree of leakage, so providing a direct and independent measure of leakage with aging.