The Application of NIR Spectrometer for Average Temperature Measurement in Optical Fibers Based on Spontaneous Raman Scattering for DTS Applications

Continuously excited Raman scattering in optical fibers is proposed for temperature remote sensing in a Distributed Temperature Sensing (DTS) system. Such an approach is suitable for average temperature measurements over the entire optical fiber or in the chosen set points. The system is operating at 1550 nm to achieve long distance temperature applications. This paper proposes the use of sensitive NIR spectrometer instead on WDM splitter. It allows controlling and choosing the appropriate wavelength of the Raman Anti-Stokes and Raman Stokes backscattered radiation. Moreover, two different types of optical fibers were tested in order to verify the DTS system capabilities, and to present the different impact of temperature upon different optical fibers types. The obtained results were satisfying and promising.