Dual channel and fast response optical fiber temperature detection system based on Raman scattering

In order to monitor the early fire situation caused by coal spontaneous combustion or cable aging, cable heated, cable overcurrent and other reasons, a dual channel and fast response temperature detection system is designed based on the Raman scattering principle in which anti-stokes signal in back Raman scattering is sensitive to temperature. The performance of the temperature detection system is obtained through experiments. The experimental data shows that the maximum error of temperature measurement is 0.7°C, the stability is 1°C in 30 minutes when both channels carry 2.5km sensing fiber, single channel response time is less than 17s and position-calculated error is less than 2m. This system would have a good application prospect in distributed fire detection and early warning under mine.