Capped ceramic underwater sound projector: The "cymbal" transducer

A new type of transducer has been developed for use as a shallow-water soun d projector at frequencies below 50 kHz, Dubbed the "cymbal," it is similar to the more commonly known "moonie" and class V ring/shell flextensional d esigns. Prototype cymbal arrays 2 mm thick with a radiating area of 11.4 cm (2) have been developed and calibrated. Two mounting schemes have been exam ined: unpotted (oil-filled) and potted in a 5-mm thick layer of stiff polyu rethane. In both cases, a transmitting response comparable to the more wide ly used Tonpilz transducer (with an equivalent radiating area) is attainabl e. When tested under hydrostatic pressures, a standard cymbal configuration has been shown to withstand exposures of 2.5 MPa (which corresponds to 250 m of water depth) before failure. (C) 1999 Acoustical Society of America. [S0001-4966(99)02801-5].