Accurate temperature measurement is a key parameter in inspection and control, and has always received great attention. Today, with the rapid development of science and technology, accurate measurement of temperature information has even broader practical significance. Distributed fiber optic temperature sensing technology has become a remarkable new technology in the field of optical fiber sensing because of its ability to continuously and instantly measure the temperature field along the fiber. This technology has been widely used in the electric power industry, petrochemical equipment, aerospace industry, nuclear industry and other fields. The common distributed fiber optic temperature measurement method is to obtain the intensity ratio of anti-Stokes to Stokes light, then apply attenuation compensation to the reference data, and finally calculate the temperature according to the demodulation formula. However, in practical applications, the signal transmitted by the optical detection module is not the intensity of anti-Stokes light and Stokes light at different positions of the fiber, but the intensity after backward propagation and attenuation loss in the fiber. Therefore, attenuation compensation must be applied to the signal transmitted by the optical detection module.

The distributed fiber optic temperature measurement method performs piecewise linear fitting on the reference signals of anti-Stokes light and Stokes light intensity according to the fiber attenuation point data, then divides the measured reference line data by the fitted baseline data and calibrates the result to obtain the fiber temperature. This product extends the application scope of distributed fiber optic temperature measurement, enabling normal temperature measurement even when the fiber quality is poor. In addition, this product applies piecewise attenuation compensation to the reference signals of anti-Stokes and Stokes light intensity, so that the temperature curve demodulated by the system matches the actual situation, thereby improving the temperature measurement accuracy and stability of the system.