Thick film device for the detection of NO and oxygen in exhaust gases

Diffusion limited amperometric yttria stabilised zirconia sensors with two consecutive electrodes can be used as a combined broad band lambda/NO sensor for the analysis of automotive exhausts. At an appropriately low pumping voltage, the first electrode removes all oxygen from the gas, but not the NO, which can only be pumped using higher cathodic potentials. The NO is then reduced at the second electrode. The pumping currents at the two electrodes are connected to the amounts of oxygen and NO. This paper reports on the fabrication and performance of a screen printed version of such a sensor. The sensors are self-heated with dimensions ready for use in real exhausts. (C) 2003 Elsevier B.V. All rights reserved.