Sensor probe for measuring hydrogen concentration in molten metal and method for measuring hydrogen concentration

摘要

On the inner surface of sensor element made of proton conductive solid electrolyte with perovskite structure and enclosed at its lower end, a reference electrode constituted of porous electrode is formed, and a measuring electrode constituted of porous electrode is formed on the outer surface thereof. And, the reference electrode and the measuring electrode are gas-tightly separated by sealing material. The sensor prove is inserted into ceramic sensor holding cup and both are fixed in such a way that a part of the measuring electrode extrude into said holding cup. Then, by dipping the holder into molten metal by facing its opening part downwards, a space contacting with molten metal is enclosed in the holding cup. Thereby, reduction of solid electrolyte constituting the sensor element can be prevented, and hydrogen concentration in molten metal can be accurately measured without direct dipping the sensor element into molten metal. Thereby, it is possible to provide a sensor probe and a method for measuring hydrogen concentration in which hydrogen concentration can be continuously measured for long period and an apparatus with smaller size can be made.