The Hardware Circuit Realization And Research On Time-difference-type Ultrasonic Flowmeter

Nowadays, during industry manufacture and science research, flowmeter is necessary. Ultrasonic flowmeter is applied widely in virtue of its advantages, such as non-contact and installation and maintenance with ease. However, it also has some disadvantages, thus it is necessary to make modification and improve.Time-difference-type ultrasonic flowmeter is studied in this paper. After many references about the ultrasonic flowmeter, the paper makes deep research on several vital techniques to advance the capability of the whole system. In addition, it supplies the design of hardware circuits and logic control. Generally, there are four parts as follows:1. Research the measurement theory of wide-beam time-difference-type ultrasonic flowmeter, derive the formula of wide-beam time-difference-type ultrasonic flowmeter, bring forward the "sing-around" method and discuss the method to improve precision. Then ultrasonic flowmeter was corrected according to the theory of hydrodynamics and physics, and calculation formulae of the flow revision coefficient are given under different states.2. According to the requirements of design. analyze and design hardware circuit of the time-difference-type ultrasonic flowmeter in detail, including the choice of circuit component and parameter, the design of the circuit of singlechip and FPGA, the design of high performance emitting and receiving circuits. Meanwhile, discuss the principle and parameter of transducer.3. Take the requirements of design into consideration, design the logic control in FPGA, and realize the drive impulse of emitting circuits, the counter of time, the counter of leak receiving time, the logic control of receiving signal, the change for receiving and emitting circuits, the communication of singlechip and FPGA, the logie of correction time. At last, realize the control logic of the system.4. Analyze and study various factors which influence flow measurement. In the end. the hardware and software are validated, the result is achieved, and the methods of improvements are given.