An electrochemical ion sensor and a method for sensing a presence of at least one ion species in a solution are provided. The electrochemical sensor includes a solid-state electrolyte medium doped with an organometallic material, having an electrochemical affinity with the ion species, and a pair of electrodes electrically contacting the solid-state electrolyte. The electrochemical sensor also includes an electrical circuit configured to drive the pair of electrodes with an AC electrical excitation and to measure at least one parameter related to a complex electrical impedance of the doped solid-state electrolyte medium in response to the AC electrical excitation. The parameter may be an electrical resistance, an inductance or a combination of both, and represents the presence of the ion species in the solution when the solid-state electrolyte medium is exposed to the solution.

A potentiometric oxygen sensor for measuring the oxygen concentration of a liquid metal, including: a metal tube forming at least one sensor body part; an electrochemical subassembly containing an electrolyte, intended to be in contact with the liquid metal, and a reference electrode contained in the electrolyte, the electrolyte being made of yttrium-doped or calcium-doped hafnia (HfO.sub.2), or of thoria (ThO.sub.2), which is optionally yttrium-doped or calcium-doped, or of yttrium-doped or calcium-doped zirconia (ZrO.sub.2), the reference electrode containing at least one metal and its oxide form at the operating temperature of the sensor, an insert made of a transition metal from group 4 of the Periodic Table or an alloy thereof, arranged between the sensor body part and the electrolyte, the insert being attached to the sensor body part and brazed onto the electrolyte by a brazing joint.

The present disclosure relates to solid electrolyte containing MgO partially stabilized zirconia doped with at least one of Mn and Co.

A potentiometric oxygen sensor for measuring an oxygen concentration of a liquid metal, which includes a metal tube forming at least one sensor body part, an electrochemical subassembly, and an insert made of a transition metal from group 4 of the Periodic Table or its alloy. The electrochemical subassembly contains an electrolyte, intended to be in contact with the liquid metal, and a reference electrode contained in the electrolyte, the electrolyte being made of yttrium-doped or calcium-doped hafnia (HfO.sub.2), or of thoria (ThO.sub.2), which is optionally yttrium-doped or calcium-doped, or of yttrium-doped or calcium-doped zirconia (ZrO.sub.2). The reference electrode contains at least one metal and its oxide form at the operating temperature of the potentiometric oxygen sensor. The insert is arranged between the sensor body part and the electrolyte, and is attached to the sensor body part and brazed onto the electrolyte by a brazing joint.

The invention relates to an oxygen detecting element comprising a coated pin and a method for measuring the oxygen content of a metal melt with an oxygen detecting element. The coated pin comprises an electrically conductive core, which is eccentrically arranged in a coating. The coating comprises at least a two-layered coating section with an inner coating layer comprising a reference material and an outer coating layer comprising an electrolyte material. The invention further relates to an immersion sensor comprising the oxygen detecting element and a method for measuring the oxygen content of a metal melt with such an oxygen detecting element.

An oxygen detecting element, comprising a coated pin. The coated pin comprises an electrically conductive core with a tapered section towards one end. The coating comprises a two-layered coating structure on a tip portion and a three-layered coating structure on a main portion of the electrically conductive core, wherein the tapered section has the same length or is longer than the tip portion. The invention further relates to an immersion sensor comprising the oxygen detecting element and a method for measuring the oxygen content of a metal melt with such an oxygen detecting element.