Pressure Dependence of Cymbal Transducers

The hydrostatic pressure limit that a receiver can withstand without failure is of major importance in underwater sonar systems. In this paper, the hydrostatic pressure tolerance and sensitivity of cymbal receivers were investigated. The failure mode in cymbal transducers under hydrostatic pressure is described. Effects of cavity geometry and material selection on hydrostatic piezoelectric coefficients and pressure limits were evaluated using both experimental data and finite-element analysis (FEA). It was found that cavity depth has a very strong effect on the stability of underwater sensitivity and pressure tolerance of these devices. Cymbals made with soft piezoelectric transducers (PZTs) possess higher figures of merit and better pressure tolerance than those made with hard PZTs. Alternatively, the cymbal sensitivity and pressure tolerance can be improved by changing the cap material.