为了消除光源强度波动对测量结果的影响,根据溶液浓度与其折射率的关系和光纤法布里-珀罗(F-P)干涉仪透射光谱中心波长与干涉仪腔内介质折射率之间的关系,利用其透射光谱的中心波长进行透明溶液浓度的精确测量,开发出测量实验系统。采用可调光学滤波器对传感信号进行采集。对浓度为5%～80%的酒精进行了实际测量实验,浓度最大测量偏差为0.003%。该系统具有如下特点

To essentially eliminate the measurement errors arisen from light source power fluctuation, a measurement method of solution concentration was proposed. The method is based on the relationship between transmission optical spectrum central wavelength of fiber Fabry-Perot (FFP) interferometer and the refractive index of medium in the cavity, as well as the relationship between solution refractive index and its concentration. Such a measurement system was developed. A tunable fiber optical Fabry-Perot (F-P) filter was used to collect the sensing data. Different concentrations of a set of alcohol solution, with the concentration being from 5% to 80%, were measured experimentally. The maximum absolute measurement bias is no more than 0.003%. This measurement system possesses following advantages