Calibration auto-correction method in Raman distributed temperature sensing system using fiber coil configuration

A novel method to auto-correct the fluctuation of calibration in Raman distributed temperature sensor is proposed in this paper. The proposed scheme combines a fiber coil configuration with a Pt-resistance in the front section to cancel out the impact of fluctuation generated by perturbations of the laser and APD, instability of power supply and environment temperature changes. The sensor performance is significantly improved by exploiting the fiber coil and Pt-resistance to correct the temperature calibration. Our theoretical analysis shows that with the calibration of temperature autocorrection method the sensing system is more suitable for various environments and provides low uncertainty in long term operation, and it has the potential to accurate temperature calibration with simple equipment and to reduce costs of the system.