Patent ID: 8071012

Claim:
A temperature measuring device for molten metal comprising a porous plug having a first end and an opposed second end, an outer protective sheath having a closed end, the outer protective sheath extending away from the first end of the porous plug, an inner protective tube having a closed end, the inner protective tube being arranged within an interior of the outer protective sheath, and a thermocouple arranged within an interior of the inner protective tube, wherein the porous plug comprises a substantially refractory material and the outer protective sheath consists essentially of substantially refractory metal oxide and graphite; wherein the second end of the porous plug is in contact with a source of inert gas and the porous plug is configured to inject a sufficient amount of the inert gas into the molten metal from the first end of the porous plug to cause movement of the molten metal at the first end of the porous plug; and wherein a junction of the thermocouple is proximate to the closed end of the inner protective tube.