Research And Design Of Intelligent Metal Variable-area Flow-meter

The flow-meter is a volume flux measuring device based on the principle of a floater ascending or descending in the vertical cone-shaped tube with the flux changing, and it’s also called rotor flow-meter. In America and Japan, this flow-meter is usually called variable area flow-meter. In order to solve the problems of the traditional metal tube flow-meter, the design uses non-contact angular measurement in measuring flux.In chapter one, the thesis introduces the research background, the recent development in flux measuring, and describes the operational principle and structure of the flow-meter.In chapter two, at the beginning of the content is the feasibility analysis of the research. Next, it introduces the performance and characteristic of the microcontroller used in the design and mainly expounds the hardware design about how to get the signal of flux, temperature and pressure. At last, it introduces the amplification and filtering of the output signal.In chapter three, the thesis narrates the intelligent methods in hardware and software design in detail. The intelligent methods used in this design include regulating the amplifier’s zero output, dealing with the magnetoresistive sensor’s bridge offset, and realizing the temperature compensation and linearity of the magnetoresistive sensor’s output. In this chapter, it also expounds a new method used to implement the temperature and pressure compensation of the density.In chapter four and five, the thesis mainly introduces the signal’s output, display and communication using CAN bus. The thesis expounds how to design the metal variable-area flow-meter of4-20mA analog signals. With the function of CAN bus communication, the system can exchange data with the computer and modify some parameters.In chapter six and seven, the thesis analyses the experimental results, summarizes the total thesis and introduces some theories that need more researches.