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The micro flow intelligent electromagnetic flowmeter and LS rotometer study of ultra-low -power design

Author: HuJianBo
Tutor: SongKaiChen
School: Zhejiang University
Course: Mechanical and Electronic Engineering
Keywords: Micro-flow Intelligent Rectangle measuring catheter AC excitation Electromagnetic Flowmeter SCM LS rotation Ultra-low power consumption
CLC: TH814
Type: Master's thesis
Year: 2002
Downloads: 302
Quote: 1
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Abstract

From the meter in the industry began to apply to the present, the industrial production of the flowmeter two ways: First, high-precision, high-performance instrument development; another small lightweight, installation ease of use, performance, moderate, cheap popularity direction. This paper consists of two parts: the first part: this part of the study of micro-flow intelligent electromagnetic flowmeter flowmeter the development direction of the design of high-performance, high-precision smart micro-flow electromagnetic flowmeter. More difficult to measure electromagnetic method measuring micro-flow analyzes. According to the analysis of the results, in the the flowmeter sensing part of the rectangle measuring catheter instead of the traditional round measuring catheter generate magnetic induced electromotive force. Next rectangle measuring catheter to be modeled, and the size of the induced electromotive force, fluid pressure loss in the measurement catheter and the sensor internal resistance of the impact of the size of the output signal is generated when the fluid flows through the rectangular measuring duct several aspects with the circular measurement catheters were compared based rectangle measuring catheter is fully capable of complete micro-flow measurement. This measure electromagnetic method using micro-flow conditions to establish a theoretical foundation. Secondly, part of the analysis of the current excitation advantages and disadvantages of the traditional 50Hz AC excitation method and square-wave excitation method, using micro controller adjustable frequency, low-frequency sine wave current excitation method. Respect 50Hz AC excitation, this excitation method can be used to lower the frequency of the magnetic circuit of the micro-flow excitation frequency interference, one can completely eliminate the orthogonal interference, on the other hand can be greatly reduced; respect to the side wave excitation, this excitation method is equivalent to more than the value of the square wave excitation, is conducive to eliminate or reduce the differential interference excitation of the square-wave method. Shortly thereafter, in the part of the micro-flow electromagnetic flowmeter converter, designed circuit to eliminate or greatly reduce the phase interference, the orthogonal interference and 50Hz frequency interference and other interference signals, traffic signal is restored and enlarged to 0 to 2.5 V between. Finally, the flow rate voltage signal after A / D sample input to the microprocessor. After the processing of the microprocessor to complete a variety of display, control and communication functions, highly intelligent flowmeter. Second part: LS rotometer the ultra-low-power design flow meter development direction to design ultra-low power consumption, small size, high performance LS rotameters. The power consumption has been plagued by the flowmeter single table design. The single phenotype flowmeter are unable to reduce the power consumption to be sufficient to battery-powered, up simply using battery-powered. The this topic devised the LS rotometer real achieve ultra-low power consumption, using dry batteries long-term supply. Firmly grasp the power problem, respectively, from sensors and other input channel selection and operation mode of the microcontroller, LCD sensor output channel and battery power and choice of ultra-low power consumption LS rotometer, analysis, and design. The final design of the entire system to achieve ultra-low power consumption. The flowmeter of this part of the study of fluid medium, no special requirements, so a wide range of applications. More importantly, low power consumption, the flowmeter system is particularly suitable for measuring the flow in the case of electricity powered from. Mentioned research a variety of ultra-low-power design principles and ideas can be applied to the circuit design. The innovation of this paper is the use of a rectangle measuring catheter greatly increase the induced electromotive force in the micro-flow conditions; adjustable output frequency sinusoidal current excitation current to achieve the elimination 50HZ frequency interference and orthogonal interference reduction purposes; such as use of single-chip high-end The modern electronic products the LS rotometer to achieve a long-term supply of highly intelligent and design of electromagnetic flowmeters real ultra-low power consumption, can be used dry batteries.

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CLC: > Industrial Technology > Machinery and Instrument Industry > Instruments, meters > Thermal measuring instruments > Flow Meter
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