光学 精密工程, 2014, 22 (1): 18, 网络出版: 2014-02-18
溶液浓度变化实时检测系统的设计
Design of real-time measurement system for solution concentration changes
数字信号处理器 视频处理 马赫-曾德尔干涉仪 浓度检测 折射率测量 digital signal processor video processing Mach-Zehnder interferometer concentration measurement refractivity measurement
摘要
设计了一套基于DSP视频信号处理的浓度检测系统,用于实时动态监测溶液的二维浓度分布变化。利用马赫-曾德尔干涉仪检测溶液折射率变化,用CCD现场记录干涉条纹,最后用DSP实时处理干涉条纹视频图像以获取溶液浓度变化。介绍了系统的硬件框架以及视频信号处理算法。实验测试显示,该系统能对单一溶质溶液浓度变化进行实时定量检测; 在多溶质条件下,通过分析主要溶质浓度的变化,能定量估算主要溶质的浓度变化。以铁在浓度为0.5 mol/L的H2SO4溶液中、扫描速度为2 mV·s-1的动电位极化实验为例,测得阳极活化区的电位为-0.428 V时,电极/溶液界面处FeSO4的浓度峰值为(9.2±0.2)×10-3 mol/L。实验结果表明,该系统精度较高,稳定性好,能够对溶液浓度变化进行实时在线检测。
Abstract
A concentration measuring system based on DSP video processing was established to monitoring dynamically two-dimensional concentration changes for solution. The refractive index changes of the solution were detected by a Mach-Zehnder interferometer, and the interferometric fringes were recorded by a CCD on site. Finally, a DSP was used to process the video images of interferometric fringes to obtain the solution concentration changes. Furthermore, both the hardware platform and the video-processing algorithm of the system were described in detail. The experimental test indicates that the system can provide quantitative measurement for a single-component solution and a multiple-component solution with one main component change. An experiment on potentiodynamic polarization of the electrode in the H2SO4 solution with a concentration of 0.5 mol/L at 2 mV·s-1 shows that the peak concentration of FeSO4 solution at the electrode/electrolyte interface is (9.2 ± 0.2)×10-3 mol/L when the iron electrode potential is -0.428 V. The system has high precision and strong stabilization in online testing and can be employed in measurement of the concentration changes of the solution in real time.
袁博宇, 李威, 罗成名. 溶液浓度变化实时检测系统的设计[J]. 光学 精密工程, 2014, 22(1): 18. YUAN Bo-yu, LI Wei, LUO Cheng-ming. Design of real-time measurement system for solution concentration changes[J]. Optics and Precision Engineering, 2014, 22(1): 18.