A Determination of the Response Characteristics of Underwater Electrostatic Transducers

Abstract

High-frequency electrostatic transducers have recently found many applications as transmitters and receivers of ultrasonic waves in gases, in a frequency range extending to one megacycle. The flat response over wide bands of frequencies, characteristic of condenser microphones in general, has made possible relatively accurate studies of sources of acoustic impulses, such as electrical discharge, in the laboratory. With an extension of operation to a more dense medium, such as water, one would expect changes in the transmitting and receiving response characteristics. This paper describes several such changes which occur when a typical high- frequency electrostatic transducer, previously demonstrated to be useful for electrical discharge studies in air, is operated underwater. Results from this study indicate some problems which arise and basic response changes which occur when a transducer of this type is operated in a medium appreciably more dense than air.