Abstract: Abstract: To improve the applicability of fiber optic sensors in building fire warning, this study conducts high temperature experiments on single-mode and multi-mode fiber optic sensors based on fire temperature rise curve, and analyzes their temperature sensing performance, and then selects the sensor whose temperature sensing performance suits building fire better. Based on the experimental data, a temperature rise error correction model was established to improve the temperature measurement accuracy. The results show that the multimode fiber optic sensor is much better than the single-mode fiber optic sensor in terms of temperature measurement stability, and has more correction value. The temperature rise error correction model built can lower the temperature measurement mean absolute error to 13.12 ℃. Using distributed optical fiber to draw high-precision building fire map has become the technical key of fire monitoring and early warning, evacuation and rescue, and structural collapse prediction.

Key words: Key words: distributed optical fiber, fire empirical model, temperature sensing performance, heating curve, curve fitting