Application of oxygen sensors in industrial glass melting tanks

Abstract

Α comparative study of electrochemical oxygen sensors for glass melts employing zirconia solid electrolytes developed by Schott Glaswerke and by the HVG is reported. The sensors applied in a feeder Channel of a melting tank producing green glass yielded slightly different but reproducible results despite different constructions. The zirconia reference electrodes achieved more than one year active lifetime at 1200°C. Their potentials directly compared over extended periods agreed within less than 3 mV. The potential differences of the platinum measuring electrodes were traced to temperature gradients. Newly installed platinum electrodes show "induction periods" caused by convectional and diffusional equilibration of adhering surface with bulk melt. Unexpected sudden oxygen inhomogeneities of the melt were detected and explained.