JRC Tokki has become the first company in Japan with a large-scale underwater acoustic ranging capability thanks to a portable sound-intensity system using Brüel & Kjær equipment
Ship noise affects the underwater environment, requiring acoustic assessment. Since Japan has no large-scale underwater ranging capability, JRC Tokki invested in a portable sound-intensity system from Brüel & Kjær. This static ranging system uses hydrophones mounted on a floating raft to make underwater Noise Source Identification (NSI) measurements on large vessels.
In order to get a complete characterization for the whole of the underwater structure of a ship, a portable system was needed that would enable field measurements. As the curvature of a ship’s stern and bow often varies, JRC Tokki needed a solution that could account for this by following the hull closely, at a uniform distance.
Underwater sound intensity measurements are made using phase-matched hydrophones mounted in a custom measurement jig suspended from a movable floating platform. Type 8104 Hydrophones are used at lower frequencies; the high frequency band is measured using the miniature Type 8103.
JRC Tokki can now create a complete characterization of the underwater structure using many individual measurements – a virtual “mesh” the covers the entire underwater surface of a ship. Using these measurements, contour maps can be made that give a 3D picture of the sound intensity performance of the ship’s hull.
Calibration Standard Hydrophone
A wide-range general purpose hydrophone that can also be used as a sound transmitter, making it ideal for calibration purpose. The hydrophone is supplied with 10 m waterblocked low-noise shielded cable to MIL-C-915 with BNC plug.
Miniature Hydrophone
Miniature Hydrophone Type 8103 is a small piezoelectric transducer designed for high-frequency laboratory and industrial use. The instrument is particularly useful in the acoustic study of marine animals or for cavitation measurement.
Spherical Hydrophone
Spherical hydrophone with rugged construction capable of withstanding pressures of up to 9.8 MPa (100 atm; 1000 m (3250 ft) ocean depth) and featuring exceptional directional characteristics.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.