Electromagnetic flowmeter is based on the working principle of Faraday's law of electromagnetic induction to measure the volume of fluid flow meter, because of its simple structure, no pressure loss, large measuring range, is one of the most commonly used flow measuring instrument. Capacitive electromagnetic flowmeter is a relatively new and still in the development of electromagnetic flowmeter can measure fluid, the fluid with low conductivity, mud fluids and adhesive fluids are difficult to measure using traditional electrode electromagnetic flowmeter, to expand the scope of application of the electromagnetic flowmeter, is an important direction in the research field of electromagnetic flowmeter in recent years.
In this paper, the related literatures on the capacitive electromagnetic flowmeter sensor and signal conversion circuit of the core parts of the research, the successful development of a prototype system, and passed the test in the experimental device. In this paper, the main research
1, the design of correlation detection theory into the signal converter, presents the rotating capacitor filter technology in a low signal-to-noise ratio, a new method of how the flow of weak signal from strong noise background.
2, in view of the filter output AC square wave signal has developed the rectifier sampling circuit, the experimental result surface, this circuit has the strong disturbance rejection ability, provided one kind of steady output signal voltage method
3, developed a prototype system, and in the experimental device through the experimental test, the results show that the proposed method is effective, the development of the prototype is successful.