TEMPERATURE MEASUREMENT DEVICE AND TEMPERATURE MEASUREMENT METHOD

To measure temperature distribution in the width direction of a GA steel sheet during transfer at high speed without having the influence of emissivity much changed in the process of alloying.SOLUTION: A temperature measurement device for measuring the temperature of a steel sheet having wavelength dependency in emissivity includes: an imaging part capable of acquiring a first radiance EA being the radiance of the steel sheet at a first wavelength λA and a second radiance EB being the radiance of the steel sheet at a second wavelength λB different from the first wavelength λA; and an arithmetic processing part 14 capable of calculating an apparent temperature Te using λA and λB, calculating an apparent emissivity εe using EA, λA and Te and using a radiance Lb (λA and Te) calculated from the formula of a black body radiation previously obtained, calculating an emissivity εA approximately derived using εe at the λA of the steel sheet by the formula and calculating the temperature of the steel sheet using εA.SELECTED DRAWING: Figure 2 【課題】合金化プロセスの過程で大きく変化する放射率の影響を受けずに、移動中のＧＡ鋼板の幅方向の温度分布を高速に測定する。【解決手段】放射率が波長依存性を有する鋼板の温度を測定する温度測定装置であって、撮像部が、第１の波長λＡにおける鋼板の放射輝度である第１放射輝度ＥＡ、及び第１の波長λＡとは異なる第２の波長λＢにおける鋼板の放射輝度である第２放射輝度ＥＢを取得し、演算処理部１４が、λＡとλＢとを用いて見掛けの温度Ｔｅを算出し、ＥＡと、λＡ及びＴｅを用いて、予め求めておいた黒体放射の式から算出した放射輝度Ｌｂ（λＡ，Ｔｅ）とを用いて見掛けの放射率εｅを算出し、εｅを用いて、近似的に導出して算出式により、鋼板のλＡにおける放射率εＡを算出し、εＡを用いて鋼板の温度を算出する。【選択図】図２