Developing Of Multi-functional Volume Corrector For Impulse Flowmeter

Nowadays, pipeline gas trade settlement is mostly based on the volume under standard conditions. But the volume measured by flowmeters is under working conditions and can not be directly used for settlement, which leading to the invention of volume corrector. Volume corrector is a kind of second device of flowmeters. It can detect pressure, temperature and flow of the measured media and correct the compression factor automatically in order to transform the volume from working conditions into standard conditionsThis dissertation is going to develop a novel battery-powered volume corrector. This corrector can be used with Turbine, Roots, Swirl, Vortex, Diaphragm and other flowmeters which output pulse. It transforms the volume of measured media from working conditions into standard conditions with its pressure sensor and temperature sensor, and offers a variety of complex functions such as industry control signals, full Chinese display and a lot of communication methods. The media can be measured includes natural gas, air, oxygen, nitrogen and coal gas.This paper has studied the working principle of the volume corrector, researched the sampling and processing of pressure, temperature and flow, and researched the methods of transforming gas conditions. It sets up the adaptive FFT power spectrum analysis model and compression factor correcting module AGA NX-19 and SGRGE-88 for nature gas with microcontroller through some numerical approach, and this ensures a high-precision sampling and conversion.This corrector provides multi-functional but very low-power peripheral modules which achieve the perfect combination of multi-function and low power consumption: full Chinese display and four key system improves the visibility of data showing and convenience of operation; industry control signals outputting system can provide current loop, frequency, alarm and other signals which improve the automation level of the corrector; the corrector can easily be connected to other correctors or computers to form network management system through the wireless communication networks comprised of its embedded GPRS, ISM and infrared wireless communication module; the average power consumption level is only 0.7mA and the inside battery can work for 3 years. Finally, this paper tests the pressure sampling, temperature sampling, flow measurement and conversion as well as other functional modules of three prototypes in order to determine the performance parameters of the corrector.