Design And Development Of Virtual Multi-channel Instrument For Flow Measurement

Flow measurement predominates an important position in agriculture, industry and scientific research. And it is very pivotal for flow measurement that the instrument for flow measurement has an outstanding performance. So it is very necessary to exploit a high-powered instrument for flow measurement. In this paper the development and status in quo about flow measuring technologies and instruments for flow measurement are fist summarized, and the characteristics and localizations of the current hardware-based instrument for flow measurement are also pointed out; And then we take the thermocouple and thermo-resistance instrument for flow measurement as the example to analyze the most representative flow measurement and the principle of instrument, including the flow measuring mechanism, physical structure and notices; An advanced manufacture technology of instrument~-virtual instrument technology and the virtual instrument based on which are introduced in succession. This paper also narrates at length the origin, characteristics and system structure. The virtual instrument and hardware-based instrument are contrasted, which stands out the superiority of virtual instrument; Finally we combine virtual instrument and the technology of flow measurement, which comes into being the virtual multi-channel instrument for flow measurement debated in detail in this paper. In the paper we amply introduce the logical structure and design of software and hardware of the virtual multi-channel instrument system for flow measurement. Applying the Object Oriented Programming(OOP) method, center control module, transmitter demarcating module, channels and scopes module, data collection and process module, data analyze module, data display module, data redisplay module, print module and the other auxiliary functions are designed, which realize the collection, process, analyze and display of the powerful virtual instrument. The experiments show that the virtual flow measurement instrument has a wile scope and flexible flow measuring mode. If users choose the right sensors, they can get the flowrate from 0 to 20m/s, and the precision is rather high. It can not only analyze the data online but also process them offline, which all shows the powerful life force of virtual instrument and the new method of flow measuring instrument. The further development of the measurement instrument for flow field measuring and distributing network measuring is finally discussed. Prof. Shuren Qin advocates that virtual instrument should be made in our country, which induces me to attempt to develop a virtual multi-channel instrument for flow measurement, and it is completed successfully in this paper.