Low oxygen activities in steel melts – Possibilities and limits of the solid electrolyte measuring technique

Review on the application of solid oxide electrolyte cells for the determination of low oxygen activities at about 0.0001 to 0.01 in steel melts. Investigation and discussion of possible error sources, such as partial electronic conductivity and oxygen ion transport in the electrolyte, reaction layers on the electrolyte surface, chemical reduction of the electrolyte and the use of inaccurate thermochemical data for the evaluation of oxygen activities, in the EMF measurement and interpretation of results. Comparison of properties of ZrO 2 ‐and ThO 2 ‐based electrolytes.