Contents 1. Introduction
Recently, an urgent need, especially in the automobile industry, for high performance gas sensors has arisen. New exhaust regulations lead to the introduction of high performance catalysts (i.e. SCR or SR-NOX catalysts), which require a precise NOx-monitoring during operation. Furthermore, in other application fields like chemical industry, aeronautics or waste incineration, the use of high temperature NOx-sensors is favoured by new specifications or standards. The requirement for these new generation sensors is to detect total NOx quantitatively at high working temperatures (e.g. 500 to 700°C), without the need for a reference electrode in a different atmosphere [1], , [3]. Therefore the major research goals are the achievement of high temperature, phase-and morphological stability up to 900°C by withholding a high sensitivity towards NOx. Also response time is becoming a more critical design parameter. In this study, we suggest a novel planar NOx-sensor design having an EB-PVD manufactured electrolyte, a RE and a NiO-SE, where both are exposed to the same atmosphere. The application of technical EB-PVD YSZ coatings as electrolyte allows the integration of these sensors into systems (i.e. catalysts) with narrow spacing, allowing placing the sensor at the point of interest. This reduces costs and furthermore decreases the response time of the system.
