A Hydrophone for Measuring Acoustic Ambient Noise in the Ocean at Low Frequencies (USRD Type H62).

摘要

A low-frequency,pressure-sensitivity hydrophone with an open-circuit crystal voltage sensitivity of -178dB re 1 V/micro Pa and a sensor capacitance of 2000 pF to provide low self noise has been developed for use at depths to 5516 m. The self-contained batteries and low-noise preamplifier are protected from high pressure and seawater by a vinyl-covered aluminum housing. Changes in the free-field voltage sensitivity are less than 1.5dB at hydrostatic pressures to 55.16MPa (8000lb/sq. in.) in the frequency range 10to 2000Hz. (Author)