Title :
Capped ceramic hydrophones
Author :
Tressler, J.F. ; Dogan, A. ; Fernandez, J.F. ; Fielding, J.T., Jr. ; Uchino, K. ; Newnham, R.E.
Author_Institution :
Int. Center for Actuators & Transducers, Pennsylvania State Univ., University Park, PA, USA
Abstract :
Attaching specially shaped thin metal caps, each containing a shallow inner cavity, to the electroded surfaces of a piezoelectric ceramic will significantly enhance its hydrostatic sensitivity. The presence of the cavities allows the metal caps to convert a portion of the incident axial-direction stress into radial and tangential stresses of opposite sign, thus allowing the amplified d31 and d33 coefficients of the poled ceramic to now add together as opposed to subtracting from one another, thus magnifying the dh . By capping a PZT-552 disk, the dh can be amplified by a factor of nearly 100 and the gh by a factor of almost 50. These particular hydrophones show the most promise for use in shallow water applications
Keywords :
dielectric losses; hydrophones; lead compounds; permittivity; piezoceramics; piezoelectric transducers; PZT; PZT-552 disk; PbZrO3TiO3; amplified d31 coefficients; amplified d33 coefficients; capped ceramic hydrophones; cymbal transducer; dielectric constant; dielectric loss; electroded surfaces; hydrostatic sensitivity; incident axial-direction stress; piezoelectric ceramic; radial stresses; shallow inner cavity; shallow water applications; tangential stresses; thin metal caps; Bonding; Capacitance; Ceramics; Fabrication; Impedance; Piezoelectric actuators; Piezoelectric transducers; Polymers; Sonar equipment; Stress;
Conference_Titel :
Ultrasonics Symposium, 1995. Proceedings., 1995 IEEE
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-2940-6
DOI :
10.1109/ULTSYM.1995.495709
