Study On Signal Processing And Liquid Pump Improving Of The Drop Analyzer

The drop analyzer is a new analytical instrument which can analyze the liquid synthetically. The analyzer can measure and discriminate liquids qualitatively and quantitatively by the affections of their physical and chemical parameters. The measurement is operated by monitoring the drop formation process under a certain measuring condition. Comparing with other liquid analysis instruments, The drop analyzer gets more physical and chemical comprehensive parameters directly or indirectly simultaneously. The drop analyzer is the ideal"green instrument"because there isn't any chemical reaction in the testing process,The drop analyzer not only has the strong synthesis testing function, but it is easy for on-line measurement and will be very useful in the liquids measuring fields of environment protection, medicine, drink and so on.A representation of volume-based fiber drop trace (VFDT) is then developed by merging Fiber drop analysis(FDA) and capacitive drop analysis(CDA), which shows the relation between the light intensity and the instant drop volume, instead of time. It makes the FDT independent from the speed of drop growth and the volatility of liquids, and accordingly ensures the reproducibility of measurement against the variation of the feeding speed of the pump. In addition, the VFDT is more favorable for fine discrimination of liquids since it improves the comparability of the FDTs of different liquids.This project aims to make the drop analysis experimental device become a dependable and practical instrumentation and to make some analysis of the experimental results of typical samples. It is the purpose of this paper to introduce the systemic project of FCDA and the implementation technology of its components, to solve and improve the problems in mechanical construction, data acquisition, signal processing and system control .The work of this thesis includes:(1) A microflow-feeding pump actuated by a single stepping motor and controlled by the computer software is devised to ensure that the drop is slowly delivered under quasi-equilibrium condition.(2) The processing circuits of fiber signal and capacitive signal are introduced in...