提高强度型光纤溶液浓度传感器灵敏度方法的研究

Study on the Method to Improve the Sensitivity of Intensity-Type Optic-Fiber Sensor of Solution Concentration

介绍一种利用光纤准直器作扩束耦合光学系统,采用低频光调制方式测量溶液浓度的光纤传感器。从菲涅耳反射公式出发推导了浓度计算的理论公式,并提出了提高测量灵敏度的方法,对食盐溶液进行了实验测定,其测量误差小于3%,实验结果表明:该光纤传感器用于测量溶液的浓度在灵敏度、精度方面都有较大的改善,并可在线连续测量或控制溶液的浓度。

In this paper, a fiber-optical sensor that uses optic-fiber collimator as optical system of the expended beam and couple, and uses the way of low frequency light modulation for measuring concentration of solution is introduced. The theoretical formulas of solution concentration have been derived from Fresnel reflection formula and the method of sensitivity measurement improving is advanced. The NaCl solution has been measured experimentally, and the measurement error is smaller than 3%. The experimental results show that the sensitivity and precision of the measuring results using the fiber-optical sensor are largely improved. It can be used to perform the measurement or the control of solution concentration on-line in succession.