Patent ID: 6626049
Filing Date: 2003-09-30
Classification: G01F

Abstract:
An ultrasonic measurement system for measuring the flow of a fluid such as gas or steam in a conduit, the system comprising:a first ultrasonic signal transducer assembly configured and aligned to clamp wholly externally on the conduit wall for energizing a region of the conduit wall with a vertically polarized shear wave energy pulse to launch an ultrasonic signal in the wall of the conduit as an axially-travelling skip signal thereby energizing a region of the conduit wall to launch mode-converted signal energy along a propagation path through fluid flowing in the conduit; a second ultrasonic signal transducer assembly which clamps to the conduit wholly externally at a location across the conduit from the first ultrasonic signal transducer and positioned in said propagation path of the mode-converted signal, the second ultrasonic transducer assembly being aligned with the propagation path through the gas in the conduit such that both the transducers are positioned in a common plane, the second ultrasonic transducer being structured and arranged to detect the mode converted signal energy propagated along the propagation path through the gas and to effectively discriminate in signal reception and perform a transit time measurement in the presence of conduit noise and short circuit energy.