Research On Testing System Of Computer-Aided Flowmeter

Flow measurement is the crucial part of modern testing technology. Electromagnetic flowmeter is an instrument extensively used in the industry process control, for its convenience of use and high precision of measurement. However, electromagnetic flowmeter has to be tested after certain period of time to ensure it is up to the standards. Traditionally, the testing uses the static flow volume method by manual operation, to compare the readings of the standard vessel to those of the flowmeter. Since it is tested by naked eyes and calculated by men, it leads to the problems of low precision and efficiency, etc.Under these circumstances, the author proposes a flow testing method based on standard flowmeter and computer controlling technology. The key factors that could improve the precision of testing system are: the precision of the standard flowmeter, the stability of the water flow and the precision of the timer/counter. So the testing system based on PC-bus technology is designed, which includes the picking up of the fuzzy signals of electromagnetic flowmeter by optical-electric separator; high performance data acquisition system (16 channel frequency input / 16 channel 18-bit analog input / 6 channel 12-bit analog output / 24 channel digital input / output); The intelligent temperature transducer is designed with on-site digital display for the temperature compensation of the system. The Endress-Hauser (E+H) promag53P (precision 0.2%) high performance electromagnetic flowmeter is used as the standard flowmeter, stabilizing the water flow with the adjustment of the electric adjustor through the compound control stratagem (CCS); designing the program for the testing flowmeter real-time with the application of Visual Basic, with windows system functions and Advantech functions.Through on-site operation of the computer floemeter test system, the system was found to be high precision, high efficiency and easy operation (by the interface of human-computer). The system attains the technological performance index as proposed, Achieving good application with the testing 0.5 degree of electromagnetic flowmeter and with the improvement of the reliability and precision of the system.