title: High-rangeability ultrasonic gas flowmeter for monitoring flare gas.
abstract: A transit-time ultrasonic gas flowmeter for high-rangeability requirements, such as those encountered in flare-gas flow-metering, is presented. The concept of ray rescue angle for the orientation of the ultrasonic transducers in single-beam transit-time ultrasonic flowmeters is introduced to overcome the problem of ultrasonic beam drift in high-velocity flows. To overcome problems associated with noise at high velocities, a chirp signal is used. To preserve the accuracy of the meter at low velocities near zero flow, a combination of chirp and continuous-wave signals is used to interrogate the flow. Overall system performance is presented, based on results from extensive wind-tunnel tests.
authors.affiliation: Dept. of Sci. and Technol., Chr. Michelsen Inst., Fantoft.
authors.forename: K S
authors.initials: KS
authors.lastname: Mylvaganam