针对传统溶液浓度测量方法的不足, 提出了一种基于光纤端面反射原理的溶液浓度测量方法。通过Fresnel(菲涅耳)定律以及折射率与溶液浓度关系, 建立了反射光强同溶液浓度的函数关系, 分析了反射光强变化的规律特征, 指出反射光强随溶液浓度变化应具有保持线性关系。并且通过蔗糖溶液和葡萄糖溶液的实验研究, 验证了反射光强随溶液浓度变化符合线性关系特性, 线性拟合度达到99%以上。该方法可用于蔗糖、葡萄糖等溶液浓度的在线测量, 具有线性度高、操作简单、易于实现特点。

For the improvement of traditional measurement method for solution concentration, a method of measuring concentration is proposed, which is based on the Fresnel principle in optical fiber. Through the Fresnel reflection formula and the relationship between refractive index and concentration, the concentration-dependent power changes are demonstrated, and the characteristics of the reflected power changes are also analyzed correspondingly. The reflected power should change with the variation of solution concentration and keep a good linearity. Furthermore, the experimental research prove the linearity between the power and solution concentration by using the sucrose solution and glucose solution, and the linear fitting factor is more than 99%. This method can be used for on-line measurement of the concentration of sucrose, glucose and other solutions, which has high linearity, simple operation, and easy to be operated.