Sensor element for a measurement probe, especially to determine the oxygen concentration in an IC motor exhaust gas, has electrodes with a solid electrolyte within porous protective diffusion layers

摘要

The sensor element for a measurement probe, especially to determine the concentration of a gas component in a gas mixture e.g. the oxygen concentration in an internal combustion motor exhaust gas, has electrodes (12,13) forming a pump cell together with a solid electrolyte (11). One electrode is exposed to the gas through a porous protective layer (18,19). A reference electrode (17) at the electrolyte is exposed to a reference gas i.e. air through a reference gas channel (16), forming a concentration or Nernst cell using one of the electrodes as a reference. The porous layer has a coarse pore structure, and both electrodes can be used selectively for the Nernst cell.