Development of monitoring and early warning fiber sensor of water inrush from coal steam floor

Aiming at the the special requirement of water inrush from coal steam floor monitoring and early warning system on stress sensor, according to the fiber Bragg grating sensing technology, the new fiber stress sensor is developed. The fundamental properties, service temperature range and fatigue durability of sensor system are tested. In 0 C ～ 40 C, the sensitivity coefficient of developed sensor is 1.23 pm/, the strain range is 1 000 , the transverse effect is 0.39 %, the mechanical hysteresis is 1.18 , the creep is 1.53 , the linearity is 0.13 %, the repeatability is 0.16 %, and the performance meets the design requirements. Results show that the new fiber sensor can fully satisfy the requirement of data acquisition of the real-time monitoring and early warring system under the condition of water inrush. Through the monitoring and early warring experiment on the mining face 9 028, the practicality and efficiency of new fiber sensor which used for the water inrush from coal steam floor monitoring and early warning system are able to be carried out within the range of 80 m from the monitoring points.