Ceramic Chemical Sensors: An Overview
Electrostatic potential drops across interfaces caused by the exchange of ions together with electrons may be used in various ways to measure the concentration of chemical species. Potentiometric sensors make use of thermodynamic equilibration between the gas and the solid electrolyte (type I and II) or the gas and a predominantly electronically conducting mixed conducting electrode in combination with a junction at the electrode/electrolyte interface (type III). Kinetic sensors make use of the transfer of ions across interfaces under non-equilibrium conditions and relate the rate determining process to the concentration of the gas. Response time, selectivity and sensitivity effects are discussed.
W. Weppner "Ceramic Chemical Sensors: An Overview", Advances in Science and Technology, Vol. 45, pp. 1809-1817, 2006