METHOD AND APPARATUS FOR MEASUREMENT OF TEMPERATURE OF MOLTEN METAL

PROBLEM TO BE SOLVED: To obtain a temperature measuring method, for a molten metal, in which a temperature can be measured with higher accuracy by judging whether the immersion state of an optical fiber is good or not. SOLUTION: A radiation thermometer 2 is connected to the base end of an optical fiber 1. The tip part of the optical fiber is inserted into a molten iron flow 10. Light which is guided through the optical fiber is divided into two beams of light whose wavelength is different. Instruction temperatures are found regarding the respective beams of light. Whether the difference between the two instruction values is at a prescribed threshold value or lower is judged by a judgment device 27. The instruction value at the threshold value or lower is judged in such a way that a molten iron temperature indicates a true temperature.