Application of quadrupole mass spectrometer for the analysis of near-surface gas composition during DC sensor-tests

This work deals with the results obtained by a new, fully computer controlled, complex experimental set-up planned and built at the Department of Atomic Physics, TU Budapest, offering the possibility to measure the resistance of high temperature chemical sensors together with the simultaneous compositional analysis of the near sample gas region. The apparatus consists of a special flow-type quartz microreactor, coupled to a quadrupole mass spectrometer through a capillary. The applied constant voltage resistance measurement method minimises the sensor polarisation due to the measuring current. As model reactions the oxidation of several reducing gases like ethanol and acetone was chosen in the 25 to 900 degrees C temperature range using the sputtered thin layer SrTiO3 sensor. The chemical reactions are compared and discussed using both self- and oven-heating. (C) 1998 Elsevier Science Ltd. All rights reserved.