抗恶劣环境的保偏光纤温度传感器

基于应力型保偏光纤传输常数差对温度的敏感性并利用偏光干涉技术,提出了一种反射型保偏光纤温度传感器并推导出传感方程。在传感器中采用宽谱光源抑制了输入/输出光纤中偏振耦合引起的误差,特性分析表明这种传感器实用、精度高并且配置灵活。实验结果与理论完全吻合,其噪声等效可探测温度精度达0.01℃。根据大型电力变压器的绕组温度监测要求,研制出一套远程多路温度传感器系统。采用特殊的涂覆和密封石英毛细管封装技术,保证光纤传感头能在热油及250℃的高温下工作,而且具有很高的绝缘性。检测结果表明传感器在0~200℃内,达到了±0.5℃测量精度。

Practical Polarization Maintaining Optical Fiber Temperature Sensor for Harsh Environment Application

A reflection spot temperature sensor was proposed based on the polarization mode interference in polarization maintaining optical fiber(PMF),and the sensing equation was obtained.In this temperature sensor,a broadband source was used to suppress the drift due to polarization coupling in lead-in/lead-out PMF.The characteristic and performance investigation prove this sensor is practical and flexible and precision.Experimental result fits the theory model very well and the noise-limited minimum detectable temperature variation is less than 0.01 ℃.For the demand of field hot-spot monitoring of huge power transformers,a remote multi-channel temperature sensor prototype was made and tested.Specially coated Panda PMF that could stand high temperature of up to 250 ℃ were fabricated and used as probe fibers.The sensor probes were sealed within thin quartz tubes of high voltage insulation and could work in hot oil and vapor envi ronment.Test results show that the accuracy of the system is better than ±0.5 ℃ within 0~200 ℃.