Fiber optic pyrometer and its application in hot-blast stove temperature measurement

Introduced in this paper are a technique of fiber optic dual-wavelength pyrometer and its principle, structure and characteristics. It was successfully applied under the hostile environment in hot-blast stoves to measure high-temperature. The efforts to overcome all difficulties, such as pressure, water vapor, and probe bend caused by thermal expansion, are reported in details. The resulting device is reliable, stable and accurate, and has immunity to harmful gas corrosion. The proposed pyrometer has a long lifetime. Therefore, it can replace the conventional thermo-electric-couple for temperature measurement in a blast furnace.