Development And Study Of Ultrasonic Flowmeter Based On Type Of TDC-GP21

Ultrasonic flowmeter is used to measure the flow of liquid through the liquidvelocity information carried by ultrasonic signals traveling across the flowing fluid.Ultrasonic flowmeter has been widely used in electric power plant, oil industry, chemicalindustry and waterworks in virtue of its many advantages, such as no disturbing flowing fluid,no medium leakage, no pressure loss, no requirements of corrosivity and conductivity ofliquid, as well as wide measuring range, high precision. In this thesis, by absorbing andreferring to the domestic and foreign advanced design experience, the author developed a newtime difference ultrasonic flowmeter based on high precision time to digital conversion chipTDC-GP21, achieved higher integration, higher precision and lower power consumptionultrasonic flow scheme.The domestic and foreign development situation and characteristics of ultrasonicflowmeter are analysed in the thesis; The basic principle of time difference ultrasonicflowmeter detection technologies is studied; The key technology of time difference ultrasonicflowmeter—high precision time interval measurement method is discussed; A new design ofultrasonic flowmeter is put forward: new generation and high precision time digitalconversion chip TDC-GP21of ACAM company as the timing measuring core, Ti company’s16ultra low power MCU MSP430F417as the main control chip.The structure of the system hardware design: taking MSP430F417as the core of systemcontrol, it is used to control flow measurement process and calculate flow data; takingTDC-GP21as the core of timing measurement, it is used to generate ultrasonic pulse signal,measure the transit time of the ultrasonic pulse accurately, and detect receiving signal; inputand output module mainly completes the display of flow information and achieve systemparameters setting through the key.The software design of the system uses IAR Embedded Workbench as developmentplatform. The control program is mainly composed of main program module, timemeasurement module, the keyboard and display module, data processing module. The thesisexpounds the principle and working process of main program module, time measurementmodule and keyboard display module.Field tests show that the system has stable operation and high measuring accuracy; Itbasically achieves to the design requirements. The system lays a good foundation indeveloping high performance ultrasonic flowmeter in the future.