TEMPERATURE MEASURING METHOD AND TEMPERATURE MEASURING DEVICE OF STEEL PLATE, AND TEMPERATURE CONTROL METHOD OF STEEL PLATE

摘要

The present invention provides a method capable of accurately measuring the temperature of a steel sheet for a long period of time without being affected by the time-dependent change of the emissivity of a reference plate (reflecting plate) and the variation of the emissivity of the steel sheet and of being carried out by a measuring apparatus capable of being easily installed as compared with a measuring apparatus for carrying out measurement using multiple reflection, a measuring apparatus for carrying out the measuring method, and a temperature control method capable of still more accurately controlling the temperature of the steel sheet. A reference plate 2 provided with a temperature controller 5 is disposed opposite to a steel sheet 1. The reference plate temperature T 2 of the reference plate is measured directly by a contact thermometer 6. A radiation pyrometer 7 is trained on the steel sheet 1 at an angle such that alternate reflection of radiation energy by the reference plate and the objective steel sheet occurs once or twice. The radiosity of the steel sheet 1 is measured by the radiation pyrometer7. A temperature obtained by converting the radiosity into a temperature of a blackbody that radiate energy equivalent to the radiosity is used as a radiosity temperature T g . The temperature controller 5 executes a control operation to make the temperature T 2 of the reference plate coincide with the radiosity temperature T g . The radiosity temperature T g is used as the temperature of the steel sheet 1.