Development Of Hardware For Two Kinds Of Digital Vortex Flowmeters

Digital signal processing technology and low-power technology have been the hot spots of researching vortex flowmeters in recent years. According to different applications and requirements of our partners, we developed two kinds of digital vortex flowmeters. One is the microcontroller - MSP430 based digital vortex flowmeter with low-power and two-wire, and the other is the digital signal processor– dsPIC based digital vortex flowmeter with high anti-jamming ability.The digital Vortex Flowmeter with low-power and two-wire combines the digital spectral analysis with analog band-pass filters to filter noises contained in the vortex signal with the greatest extent and works at low-power. In order to provide the maximum current for the meter the DC/DC with high efficiency and low-power is used for converting power from high voltage in the system. A kind of differential amplifier is developed using three amplifiers to acquire the vortex signal effectively and filter the common-mode noise. The temperature and pressure compensation module is built so as to measure the gas flow-rate accurately.The digital vortex flowmeter with high anti-jamming ability adopts both the spectral analysis based on FFT and the notch filter to process the output signal of vortex sensor, and extracts the flow-rate information from noisy vortex sensor signal. The isolated DC/DC power module is utilized to meet the requirements of the typical tests for vortex flowmeter. The communication between the meter and the upper-system is implemented through the isolated communication port.