Humidity Sensor with SrCe0.95Yb0.05 O 3 Solid Electrolyte for High Temperature Use

Abstract

A sensing system for humidity was operated at with both and gases at 873–1273 K. The system design was Pt, (reference electrode), Pt. The EMF of the sensor had good reversibility and rapidly responded to the changes of humidity and temperature. Because the solid electrolyte was a mixed conductor of protons, oxygen ions, and positive holes, the EMF for , air, , or Ar with humidity was expressed taking into account mixed conduction by where is the equilibrium constant of the reaction of . The was determined experimentally, and was measured by an oxygen sensor with solid electrolyte. For gas in both electrodes where the superscript means reference electrode. The was determined experimentally.