反射型保偏光纤温度传感器现场校准方法

设计了一种反射型保偏光纤温度传感器,介绍了其原理并给出了传感方程。分析表明:光路传输损耗变化是引起传感方程参数变化的主要原因,在需要重装光路的应用场合,需要对传感方程参数进行现场校准。结合输出信号和传感方程系数的特点和关系,将传输损耗与传感器本征参数分离,提出了一种简单实用的现场校准技术并建立了计算模型。采用该技术,在校准时只要给出传感头所处位置的一点温度值便可实现传感方程所有参数的校准。搭建了实验系统,通过改变光路传输损耗进行了校准实验,分别采用曲线拟合和模型计算方法进行了数据分析和对比,对该方法进行了验证。实验表明,在-30～60℃的温度范围内,校准前后温度传感器的精度均可达到±0.5℃。

Field calibration method for the reflection type polarization maintain optic fiber temperature sensor

A reflection type polarization maintain optical fiber temperature sensor was designed.The operation principle was introduced and the sensing equation was given.Analysis indicated that the propagation loss variety was the main factor which made sensing equation parameters change.So,in the application field where the optical path structure of sensor might be re-assembled,the parameters calibration was necessary.Based on the characteristic and the relation of sensor optical section output signal and the sensing equation parameters,the propagation loss could be separated from the sensor initialization parameters and a simple and practical field calibration method,with which the whole sensing equation parameters could be calibrated when the temperature at the sensor probe was given,was proposed and the calculation equation was established.An experimental sensor system was built and the calibration experiments were made by changing the propagation loss.The date obtained were analyzed and compared with polynomial fitting and model calculation.The result proves the field calibration technology and the sensing temperature precision can be better than ±0.5℃ before and after calibration.