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Article: In search of the vortex frequency: with DSPs, researchers can transfer some of the lessons learned in audio signal processing to industrial vortex flowmeters.(Brief Article)
- Article from:
- Control Engineering Europe
- Article date:
- February 1, 2002
CopyrightCOPYRIGHT 2002 Reed Business Information. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Vortex flowmeters are basically simple instruments measuring one variable - the frequency of the vortex caused by the shedder bar that is placed in the middle of the pipe. The vortex frequency ranges from 20 to 600 Hz and is directly proportional to the flow rate.
Instrument manufacturers have used different techniques for detecting the frequency. Some have a small mechanical fin that vibrates in the flowstream, others use piezoelectric sensors and ultrasonic techniques to sense the change in pressure, which is another way to pick up the frequency. Digital signal processing has opened up a new era for vortex flow metering because it allows the vortex signal to be ...