Patent ID: 7140765

Claim:
A device for continuous measurement of the temperature of molten metal in a furnace or recipient for its production and treatment, characterized in that it comprises a heat analysis instrument ( 14 ) placed in a lance ( 12 ) which blows compact inert gas and/or high-pressure compressed air against a top surface layer of metal slag ( 18 ) in the furnace or recipient ( 20 ) so as to create an opening in said top surface layer of said metal slag to allow said molten metal to be visible to said heat analysis instrument, a means for generating a supersonic jet of said compact inert gas and/or high-pressure compressed air ( 22 ) mounted in front of the heat analysis instrument ( 14 ), the lance further comprising a tubular structure ( 11 ) in which said heat analysis instrument ( 14 ) is inserted through a support ( 15 ), further characterized in that said instrument ( 14 ) is connected to the outside of said lance through an optical fibre ( 16 ), said heat analysis instrument ( 14 ) being a pyrometer which provides a temperature of said molten metal.