MEASURING METHOD OF CAST SLAB SURFACE TEMPERATURE IN CONTINUOUS CASTING MACHINE

PROBLEM TO BE SOLVED: To precisely measure the surface temperature of a cast slab while accurately understanding an end part of the cast slab being cast, without affected by a secondary cooling water remaining on the surface of cast slab, the steam generated from the secondary cooling water, and the white plume resulting from condensation of the steam.SOLUTION: The measuring method of surface temperature of a cast slab measures the surface temperature of the cast slab 10 which is being continuously cast, using an infrared sensing type surface temperature measuring instrument 13. The infrared sensing type surface temperature measuring instrument is used in which the measurement direction of radiation energy from the surface of cast slab is tilted from the vertical line on the surface of cast slab by a range of 1-60° along cast slab width direction. The distance between a condenser lens of the infrared sensing type surface temperature measuring instrument and the surface of cast slab is 100-800 mm. The gas of 10 NL/mil or more is jetted toward the cast slab from the infrared sensing type surface temperature measuring instrument. The gas excludes the secondary cooling water and vapor from between the condenser lens and the surface of cast slab as well as from a temperature-measurement point of the cast slab.