A Study On The Drop Analyzer Based On Fiber Signal And Image

Drop analyzing technology (DAT) can be defined as a technology of drop monitoring in the process of drop formation under certain testing conditions to discriminate different liquids qualitatively and quantitatively and to measure the physical and chemical parameters of the tested liquids. Fiber drop analysis (FDA), capacitive drop analysis (CDA), image drop analysis (IDA) and spectral drop analysis (SDA) are the main methods. FDA produces a fiber drop trace (FDT), which shows the light intensity change during the drop growth. FDT externalizes the overall properties of tested liquids and is unique under certain conditions. But it is limitative in practice because the speed of drop growth cannot be controlled precisely by a common feeding pump. A representation of volume-based fiber drop trace (VFDT) is then developed by merging FDA and 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. In addition, the VFDT is more favorable for fine discrimination of liquids since it improves the comparability of the FDTs of different liquids. And also, the combined system of fiber-Image drop analyzer (FIDA) is capable of simultaneously determining a more comprehensible range of the liquid properties. The project is supported by the NSTB-MOST Joint Research Program (Project Number: 003/101/04), where NSTB refers to the National Science and Technology Bureau of Singapore and MOST refers to the Ministry of Science and Technology of China. In order to eliminate the disturbance among different liquids, the structures of the pump and the liquid head. The change of the control method of the stepper motor to drive the pump decrease the cost of the instrument. The CCD is introduced into the instrument to get the image of the liquid drop. The instantaneous volume of the drop can be calculated by the images. And also, the liquids can be analyzed through the edges of the liquid images. The work of this thesis includes: (1) In order to eliminate the disturbance among the liquids when the analyaer measures the liquids continuously, the structures of the pump and the liquid head have been improved. After the improved, the disturbance can be eliminated in a large extent. (2) A micro-flow-feeding pump actuated by a single stepping motor and controlled by the parallel port in the computer is devised. It can meet with the demand in the drop analyzer and it can decrease the cost of the analyzer. (3) Study the method to deal with the data that collected; (4) A study on the feasibility to distinguishing the liquids on the image processing has been carried.