Temperature measurement method, temperature control method and temperature measurement apparatus for high-temperature melt

摘要

A method of measuring the temperature of a hot melt by converting into temperature a light signal transmitted through an optical fiber the leading end of which is inserted into the hot melt. The temperature measurement is cyclically executed while severing by cutting any devitrified leading end portion of the optical fiber. Peak values of measured temperature, attributable to burning of components of the optical fiber, are excluded from the results of the measurement. The temperature of the hot melt is controlled based on the measured temperature as close as possible to a lower limit temperature which when not exceeded causes a reduction in fluidity of slag on the hot melt. The temperature measurement is performed by a temperature measuring apparatus which has a device for feeding the optical fiber into and out of the hot melt and a cutting device for severing the devitrified leading end portion of the optical fiber.