为了提高分布式光纤传感系统的准确性, 理论上比较了多参数同时测量与单参数测量时温度、应变的误差标准差, 指出在典型配置下双光纤或双波长方式的同时测量误差标准差可达单参数测量法的9~850倍, 双段光纤法应变误差标准差为单参数测量法的1.4倍。采用基于伪Voigt模型的拟合算法提取布里渊频移, 计算结果验证了以上结论。

光声光谱法是检测气体最灵敏的方法,气体浓度检测精度可达到ppt量级,但这需要复杂的实验系统和昂贵的器材,不利于在工程实践上使用.本文基于可调激光器的电流调制特性,提出了一种在测量气体吸收谱的吸收零点和吸收峰之间有效切换波长的简单调制方法.当激光功率为2.1 mW时,甲烷气体浓度的测量极限可达到0.46 ppm,测量结果证明了双波长法的可行性.

In total light scattering particle sizing technique, the relationship among Sauter mean diameter D32, mean extinction efficiency Q, and particle size distribution function is studied in order to inverse the mean diameter and particle size distribution simply. We propose a method which utilizes the mean extinction efficiency ratio at only two selected wavelengths to solve D32 and then to inverse the particle size distribution associated with Q and D32. Numerical simulation results show that the particle size distribution is inversed accurately with this method, and the number of wavelengths used is reduced to the greatest extent in the measurement range. The calculation method has the advantages of simplicity and rapidness.