STABILIZED ZIRCONIA-BASED NOX SENSOR OPERATIVE AT HIGH-TEMPERATURE

An electrochemical device combining an MgO-stabilized zirconia (MSZ) t ube with an auxiliary phase of Ba(NO3)(2) was found to exhibit fairly good Nernst's response to dilute NO2 in air at elevated temperature (4 50 degrees C). The response to NO in air could be improved to be rough ly comparable to that to NO2 when Ba(NO3)(2) was added with 10 mol% Ca CO3. The EMF response of the tubular device to a fixed concentration o f NO2 or NO was strongly dependent on O-2 concentration. The effect of O-2 was much mitigated with a probe-type planar device.