This paper presents a spatially distributed fiber-optic sensor system designed for demanding applications, like temperature measurements in the steel industry. The sensor system employed optical frequency domain reflectometry (OFDR) to interrogate Rayleigh backscattering signals in single-mode optical fibers. Temperature measurements employing the OFDR system were compared with conventional thermocouple measurements, accentuating the spatially distributed sensing capability of the fiber-optic system. Experiments were designed and conducted to test the spatial thermal mapping capability of the fiber-optic temperature measurement system. Experimental simulations provided evidence that the optical fiber system could resolve closely spaced temperature features, due to the high spatial resolution and fast measurement rates of the OFDR system. The ability of the fiber-optic system to perform temperature measurements in a metal casting was tested by monitoring aluminum solidification in a sand mold. The optical fiber, encased in a stainless steel tube, survived both mechanically and optically at temperatures exceeding 700◦C. The ability to distinguish between closely spaced temperature features that generate information-rich thermal maps opens up many applications in the steel industry.


Materials Science and Engineering

Second Department

Electrical and Computer Engineering

Research Center/Lab(s)

Peaslee Steel Manufacturing Research Center

Second Research Center/Lab

Intelligent Systems Center


This research was funded by the Kent D. Peaslee Steel Manufacturing Research Center (PSMRC) at Missouri S&T.

Keywords and Phrases

Temperature Sensor; Rayleigh Scattering; Optical Frequency Domain Reflectometry; Distributed Sensing; Optical Fiber; Peritectic Behavior; Metal Casting; Aluminum Alloy

International Standard Serial Number (ISSN)

1424-8220; 1424-8220

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2020 The Authors, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

02 Jul 2020

Included in

Metallurgy Commons