| 摘要 |
The transducer housings for clamp-on transducers of a flowmeter system are cast of an aluminum zinc alloy which is sonically conductive after casting. The transducer housings have a shear mode converting surface which has a longitudinal curvature and a cross-curvature. The cross-curvature of the shear mode conversion surface defines a solid lens which tends to focus internally reflected shear mode converted energy along the line of intersection of the flat output surface of the transducer housing with a circular metal conduit. The longitudinal curvature of the shear mode converting surface adjusts the phase velocity over the transducer output surface so as to focus the beam and reduce beam spreading along the length of the pipe and generally to correct aperture dispersion. A relatively low Q transducer crystal assembly is coupled to the aluminum-zinc alloy housing.
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