SENSORS BASED ON NEW OXIDE ELECTROLYTE AND OXYGEN REFERENCE MATERIALSFOR ONLINE MEASUREMENTS IN STEEL MELTS

Oxygen sensors are helpful tools to control and monitor continuous ope rations in steelmaking processes, e.g. in ladle refining and in the tu ndish of a continuous casting system. Up to the present no suitable ox ygen probes for on-line measurements have been developed. In search of new sensors much work has been done to investigate And discuss possib le error sources which impede the use of the conventional one-reading probes for continuous measurements. In the present study modified plug -type sensors and new combined tube plug-type sensors with optimized c ell design are presented. Furthermore, new solid oxide electrolytes co mbined with new reference materials are used to reduce the flux of ion ic oxygen across the solid electrolyte and thereby minimize polarisati on effects over extended periods. It is shown that these oxygen sensor s enable reliable long-term measurements over periods of at least 5 h in Al-deoxidized unalloyed and high alloyed steel melts.