Method for reliable detection of different exhaust gas components by pulsed discharge measurements using standard zirconia based sensors

We present a measurement approach to obtain increased differentiation of exhaust gas components and stabilized signal behavior using a standard zirconia-based potentiometric lambda probe. The self-discharge characteristic after different voltage pulses applied to the sensor is used as a measured parameter which depends on gas type and concentration. The detection of NO in the lower ppm range is demonstrated. In addition, this approach allows to improve the response and selectivity to NO significantly compared to other investigated gases as NO2, NH3, H-2 and a mixture of hydrocarbons. Therefore, this technique seems to be capable to enable NO sensing in exhaust gas with improved selectivity using standard lambda probes.