Interference Principle-based And Digital Image Processing Technology, Dynamic Concentration Monitoring / Detection Methods

Concentration measurement has wide applications in Chemistry, Biology, Material and other domains. In Biology, concentration distribution of a cell is measured to analyze the live cell. During the process of crystal growing, the surveillance of concentration change at the surface of crystal is one of the main techniques to make high quantity crystal. In electrochemistry, the concentration of the solution near the electrode/solution changes during electrochemical reaction processes such as anode dissolution and cathode deposition. It is important to analyze those concentration changes for illustrate the mechanism of the electrochemical reaction processes.Digital holographic interferometry was used to measure concentration change distribution of the solution at the interface of electrode/solution during electrochemical reactions in this thesis. With the introduction of carrier fringes in digital holographic interferometry, Fourier analysis method was used to analyze interference patterns and calculate their dynamic changes conveniently. The phase difference of object wave front, which was caused by the change of the solution's concentration during the electrochemical reaction, was calculated from interference patterns to reflect the concentration change distribution. The reconstructed phase images, which were distribution of the phase difference of object wave front, reflected the changes such as concentration distribution, diffusion layer, etc. It provided a new method to detect and analyze dynamic concentration changes. Moreover, this concentration measurement system could obtain the quantitative concentration changes of single solute solution. It based on the relationship between the concentration and refractive index of the solution. It was the first time that the dynamic change distribution of the single solute solution's concentration was measured quantitatively.For the real-time measurement of concentration changes, DM642 would be used to process the video signals of interferometry fringes. Combined with the optical interferometry system, DM642 could be applied to analyze and process the digital holograms. The results which were calculated from the images might be shown on the LCD screen in real-time. We applied ourselves to study the metal electrode's corrosion processes and develop new method and system of concentration measurement in our work. This system could detect the concentration changes in real time and measure the single solute solution's concentration quantitatively. It could be applied in other domains such as biology and medicine.