Radiation thermometer for molten iron and method for measuring the temperature of molten iron

A radiation thermometer for molten metal, comprising:

• a probe tube having a closed bottom end for immersion in molten metal and an open top end;
• a radiation meter having a sensor port fixed to the open top end of the probe tube to receive radiation emitted from an inner bottom of the probe tube and thereby measure the temperature of the molten metal;
• and
• wherein said molten metal is molten pig iron or molten steel, the probe tube comprises zirconium boride ceramics, the inner bottom of the probe tue is formed into a spheroidal shape, and the entire length of the probe tube is between 20 and 700 times as large as the inner radius of the probe tube.

A radiation thermometer for molten metal, comprising:

• a probe tube having a closed bottom end for immersion in molten metal and an open top end;
• a radiation meter having a sensor port fixed at the open top end of the probe tube to receive radiation emitted from an inner bottom of the probe tube and thereby measure the temperature of the molten metal;
• and
• wherein the probe tube comprises an inner tube comprising oxide ceramics disposed inside of an outer tube comprising zirconium boride ceramics and wherein the molten metal is selected from a member of the set consisting of molten pig iron and molten steel.