基于菲涅尔反射的液体浓度精确测量系统

利用菲涅尔反射定律提出了一种测量液体浓度的新方法。整个实验装置结构简单,主要由一个激光光源、三个光耦合器、两个光电探测器组成。光源所发出的光经过三个光耦合器后传输至光纤-液体表面发生反射,反射回的光由两个光电探测器接收。在测量过程中引入参考光路,利用相对技术,使得被测液体的浓度值仅由相对接收光强R决定,从而很好地解决了光源稳定性、环境干扰等测量难题。实验以食盐溶液和蔗糖溶液为测量对象,实验结果与理论分析十分吻合。整个实验装置结构简单,测量精度高,易于操作,测量稳定性能够达到99%以上。

Precised measurement of liquid concentration based on Fresnel-reflection

A new method to measure liquid concentration based on Fresnel-reflection is presented. The experimental setup is extremely simple, which includes a laser diode, three fiber couplers, and two photodetectors. The light is sent to the diode source pass through three couplers and is reflected by the sensor-liquid interface. The reflected light is then detected by the two photodetectors. The concentration of liquid is obtained from the measured value of relative reflection intensity as a result of relative technique, which can eliminate the influence of light source fluctuation and environment interfere. Results are presented for salt and sucrose solutions, which prove that the concentration measurements are in very good agreement with theoretical analysis. The whole measurement setup can get 99% measurement stability with simple configuration, high precision and easy to operation.