Accession Number : ADD015030

Title :   Piezoelectric Ceramic Hydrostatic Sound Sensor.

Descriptive Note : Patent Application, Filed 5 Dec 90,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Kahn, Manfred ; Chase, Mark

Report Date : 05 Dec 1990

Pagination or Media Count : 15

Abstract : This invention relates to a piezoelectric ceramic hydrostatic sound sensor or transducer having one or a plurality of voids and to a method for making such a transducer. Conventional piezoelectric ceramic hydrophones employ relatively incompressible materials such as lead zirconate titanate (PZT) having the general formula (PbO) (ZrO2) 0.52 (TiO2) 0.48; PZT doped with 6-15% lanthanum oxide, La2O3 (PZLT); barium titanate, BaTiO3; lead zinc niobiate, (PbO) (ZnO) (Nb2O5); and lead magnesium niobiate, (PbO) (MgO)0.33(Nb2O5)0.67. The electromechanical response of ceramic transducers to hydrostatic pressure variations is only a fraction of their uniaxial electromechanical sensitivity because, due to their Poisson ratio, the lateral force components due to hydrostatic pressure tend to cancel out the axial compression of the material, thereby reducing the electromechanical response to hydrostatic pressure.

Descriptors :   AXES, BARIUM TITANATES, CERAMIC MATERIALS, COMPRESSION, ELECTROMECHANICAL DEVICES, FORMULATIONS, HYDROPHONES, HYDROSTATIC PRESSURE, INCOMPRESSIBILITY, LEAD TITANATES, MAGNESIUM, MATERIALS, PIEZOELECTRIC MATERIALS, POISSON RATIO, RESPONSE, SENSITIVITY, TRANSDUCERS, VARIABLE PRESSURE, ZINC, ZIRCONATES

Subject Categories : Miscellaneous Detection and Detectors
      Acoustics
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE