Temperature measurement is crucial for many industrial processes and monitoring tasks. Most of these measurement tasks can be carried out using conventional electric temperature sensors, but with limitations. Particularly under harsh conditions, fibre optic temperature sensors show their advantages over conventional instrumentation. Three common principles of fibre optic temperature measurement are exemplarily examined: fibre Bragg gratings, Raman scattering and interferometric point sensors. Their working principles along with recent findings and applications of the sensing concepts are presented. So far their application is still limited to niche markets but with decreasing system prices fibre optic temperature sensing has great potential for further growth.
1. Measures, R. Structural Monitoring with Fiber Optic Technology. Academic Press, Boston, 2001.
2. Hill, K., Fujii, Y., Johnson, D. and Kawasaki, B. Photosensitivity in optical fiber waveguides: Application to reflection filter fabrication. Appl. Phys. Lett., 1978, 32, 647–649.
doi:10.1063/1.89881
3. Meltz, G., Morey, W. and Glenn, W. Formation of Bragg gratings in optical fibers by a transverse holographic method. Opt. Lett., 1989, 14, 823–825.
4. Lee, B. Review of the present status of optical fiber sensors. Opt. Fiber Technol., 2003, 9, 57–79.
doi:10.1016/S1068-5200(02)00527-8
5. Lagakos, N., Bucaro, J. and Jarzynski, J. Temperature-induced optical phase shifts in fibers. Appl. Opt., 1981, 20, 2305–2308.
6. Bertholds, A. and Daendliker, R. Determination of the individual strain-optic coefficients in single-mode optical fibers. J. Lightwave Technol., 1988, 6, 17–20.
doi:10.1109/50.3956
7. O’Dwyer, M., Ye, C., James, S. and Tatam, R. Thermal dependence of the strain response of optical fibre Bragg gratings. Meas. Sci. Technol., 2004, 15, 1607–1613.
doi:10.1088/0957-0233/15/8/031
8. Flockhart, G. M., MacPherson, W. N., Barton, J. S., Jones, J. D., Zhang, L. and Bennion, I. Departure from linearity of fibre Bragg grating temperature coefficients. In Optical Fiber Sensors Conference Technical Digest (OFS), Portland, 2002, 15, 75–78.
9. Gupta, S., Mizunami, T., Yamao, T. and Shimomura, T. Fiber Bragg grating cryogenic temperature sensors. Appl. Opt., 1996, 35, 5202–5205.
10. Lin, G., Wang, L., Yang, C., Shih, M. and Chuang, T. Thermal performance of metal-clad fiber Bragg grating sensors. IEEE Photonics Technol. Lett., 1998, 10, 406–408.
doi:10.1109/68.661425
11. Li, X., Prinz, F. and Seim, J. Thermal behavior of a metal embedded fiber Bragg grating sensor. Smart Mater. Struct., 2001, 10, 575–579.
doi:10.1088/0964-1726/10/4/301
12. Lupi, C., Felli, F., Ippoliti, L., Caponero, M. A., Ciotti, M., Nardelli, V. and Paolozzi, A. Metal coating for enhancing the sensitivity of fibre Bragg grating sensors at cryogenic temperature. Smart Mater. Struct., 2005, 14, 71–76.
doi:10.1088/0964-1726/14/6/N02
13. Baker, S., Rourke, H., Baker, V. and Goodchild, D. Thermal decay of fiber Bragg gratings written in boron and germanium codoped silica fiber. J. Lightwave Technol., 1997, 15, 1470–1477.
doi:10.1109/50.618379
14. Chojetzki, C., Klaiberg, T., Grimm, S. and Bartelt, H. Faser-Bragg-Gitter mit anormalen Temperaturverhalten. In DGaO-Proceedings, Bad Kreuznach, 2004, 105, 2 p.
15. York Sensors Ltd. Technical aspects of optical fibre distributed temperature sensing. In Distribution and Transmission Systems (Digest No. 1997/050), London, 1997, 3–7.
16. Dakin, J., Pratt, D., Bibby, G. and Ross, J. Distributed optical fibre Raman temperature sensor using a semiconductor light source detector. Electron. Lett., 1985, 21, 569–570.
doi:10.1049/el:19850402
17. Hartog, A., Leach, A. and Gold, M. Distributed temperature sensing in solid-core fibres. Electron. Lett., 1985, 21, 1061–1062.
doi:10.1049/el:19850752
18. Wakami, T. and Tanaka, S. A long span fibre optic distributed temperature sensor. In Optical Fiber Sensors Conference Technical Digest (OFS), Glasgow, 1994, 10, 134–137.
19. Barnowski, M. K. and Jensen, S. M. Fiber waveguides: A novel technique for investigating attenuation characteristics. Appl. Opt., 1976, 15, 2112–2115.
20. Farahani, M. A. and Gogolla, T. Sponateous Raman scattering in optical fibers with modulated probe light for distributed temperature Raman remote sensing. J. Lightwave Technol., 1999, 17, 1379–1391.
doi:10.1109/50.779159
21. Feced, R., Farhadiroushan, M., Handerek, V. and Rogers, A. Advances in high resolution distributed temperature sensing using the time-correlated single photon counting technique. IEE Proc. Optoelectron., 1997, 144, 183–188.
doi:10.1049/ip-opt:19971183
22. Aufleger, M., Conrad, M., Perzlmaier, S., Porras, P. and Strobl, T. Distributed fibre optics temperature measurement on its way to become an ordinary tool in dam monitoring. In Hydro Rev. Worldwide, 2005, 13.
23. Jones, S., Bucea, G., McAlpine, A., Nakanishi, M., Mashio, S., Komeda, H. and Jinno, A. Condition monitoring system for transGrid 330 kV power cable. In International Conference on Power System Technology, Singapore, 2004, 10.
24. Lee, C. E., Gibler, W., Atkins, R. A. and Taylor, H. F. In-line fiber fabry-perot interferometer with high-reflection internal mirrors. In Proc. SPIE, 1991, vol. 1584, 396–399.
doi:10.1117/12.50964
25. Schwotzer, G. and Willsch, R. Faseroptisches Sensorsystem für industrielle Prozesskontrolle, Umweltüberwachung, Biotechnologie und Medizintechnik. In Proc. 2nd Congress for Optical Sensor Technology, Measuring Techniques and Electronics (OPTO), Leipzig, 1996, 19, 319–324.
26. Schwotzer, G., Reichelt, K., Sinn, E., Wieduwilt, T. and Willsch, R. Potential low-cost spectral-encoded optical fiber sensor system. In Optical Fiber Sensors Conference Technical Digest (OFS), Williamsburg, 1997, 12, 114–117.
27. Lee, C. E., Atkins, R. A. and Taylor, H. F. Performance of fiber-optic temperature sensor from –200 to 1050 °C. Opt. Lett., 1988, 13, 1038–1040.
28. Schwotzer, G., Wieduwilt, T., Giebel, M., Willsch, R. and Mueller, W. Low-cost optical miniature spectrometers and their application in spectral-encoded optical fibre sensors. In 4th Micro Techniques Thüringen, Technical Digest, Erfurt, 2002, 4.
