S20  Vibroacústica    Titulo: DEVELOPMENT OF A MECHANICAL IMPEDANCE TECHNIQUE FOR HIGH POWER PERFORMANCE TESTS OF HYDROACOUSTIC TRANSDUCERS IN AIR   Resumo : ABSTRACT. THIS WORK PRESENTS THE DEVELOPMENT OF A TECHNIQUE FOR HIGH POWER PERFORMANCE TESTS OF PIEZOELECTRIC HYDROACOUSTIC TRANSDUCERS IN AIR, IN WHICH A SPECIALIZED PIEZOELECTRIC TRANSDUCER, NAMED DUMILOAD ("DUMMY MECHANICAL IMPEDANCE LOAD"), IS MECHANICALLY COUPLED TO THE TRANSDUCER TO BE TESTED. BY VARYING THE ELECTRICAL IMPEDANCE PLACED ACROSS THE DUMILOAD S ELECTRICAL TERMINALS, THE MECHANICAL LOAD PRESENTED TO THE TRANSDUCER BEING TESTED IS ADJUSTED, UNTIL MATCHING THE WATER MECHANICAL IMPEDANCE. BY APPLYING THE TECHNIQUE TO TONPILZ TRANSDUCERS, THE DUMILOAD PERFORMANCE IS COMPARED WITH RESULTS OBTAINED FROM A CLASSICAL UNDERWATER CALIBRATION METHOD AND WITH ANALYTICAL RESULTS PREVIEWED BY THE THEORETICAL MODELS HERE PROPOSED. KEYWORDS: ACOUSTIC, PIEZOELECTRICITY, HYDROACOUSTIC TRANSDUCERS     Autores : Afonso, Orlando J. Ribeiro Magalhães, Fernando Luiz de     Trabalho Completo :   COBEM99 | Comissão  Organizadora | Palestras | Sessões Técnicas | Autor | Simpósios e Sessões Especiais | Revisores |  Título  dos  Trabalhos | Local