Nanorod-Cladding Sapphire Fiber for Continuous Temperature Measurement in Molten Steel

摘要

This paper reports a new optical fiber thermometer (OFT) for temperature measurement under extreme environments, such as in molten steels. The OFT probe consists of a ceramic tube and a sapphire fiber, which is coated with a nanorod cladding layer. Installed inside the ceramic tube, the nanorod-cladding sapphire fiber can collect thermal emissions of the ceramic tube and couple the emission out of the OFT probe to a near-infrared spectrometer with minimal loss of photons. The molten steel temperature was determined by analyzing the emission spectra using a polynomial curve fitting or a machine learning-based classification algorithm.