FESTELEKTROLYTSENSOR ZUR ÜBERWACHUNG DER KONZENTRATION EINES ELEMENTS IN EINEM FLUID, INSBESONDERE EINER METALLSCHMELZE

摘要

The present invention relates to an electrochemical sensor for determining the concentration of a group IA metal in a fluid such as molten metal. The sensor comprises a substantially pure quantity of the group 1A metal as a reference electrode ( 13 ) contained in a sensor housing ( 3 ), and a solid electrolyte constituting at least part of the sensor housing ( 3 ). The electrolyte is in electrical contact with the reference electrode ( 13 ) and the sensor is capable of operating at temperatures in excess of 973K. In a preferred arrangement, the sensor comprises a two part elongate conductor ( 15 ), a first part ( 17 ) of which extends from the reference electrode ( 13 ) into a refractory seal ( 11 a), and a second part ( 19 ) of which extends from within the refractory seal ( 11 a) externally of the sensor, the two parts ( 17, 19 ) being welded together.