A Hydrophone for Measuring Acoustic Ambient Noise in the Ocean at Low Frequencies (USRD Type H62)
Abstract
A low-frequency, pressure-sensitivity hydrophone with an open-circuit crystal voltage sensitivity of -178 dB 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 1.5 dB at hydrostatic pressures to 55.16 MPa (8000 lb/sq. in.) in the frequency range 10 to 2000 Hz.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 1974
- Accession Number
- AD0778336
Entities
People
- I. D. Groves Jr.
Organizations
- United States Naval Research Laboratory