Acoustic Calibration and Pressure Testing

DRDC Atlantic Fact Sheet

DRDC Atlantic Barge

Acoustic Calibration Barge

The DRDC Atlantic Acoustic Calibration Barge is located in Bedford Basin, about 5 km by water from DRDC Atlantic. The main function of the Barge is to conduct acoustic calibrations of sonar transducers such as hydrophones and projectors, in a free field salt water environment. It is also used to test and evaluate many other types of sea-going scientific apparatus and military equipment. The chief customers are DRDC Atlantic defence scientists, the Canadian Forces, other government departments and Canadian industry. It is equipped like a combined floating laboratory and workshop. The 300 tonne barge is 36 metres long by 17 metres wide. The main working area is covered by an enclosed heated deckhouse 30 metres by 13 metres, which allows calibrations to be performed year round. The hull contains a rectangular well 18 metres by 9 metres through which equipment under test can be lowered into the water. The barge is moored 1 kilometre from the nearest shore in a water depth of 42 metres. A 10 tonne crane is fitted to the outside deck for unloading equipment and a 5 tonne travelling crane is used to position apparatus over the well. Rotating stations with capacities up to 7 tonnes are available to position sonar transducers at any required orientation and depth.

The Barge is equipped to measure the performance of sonar transducers over the range 100 Hz to 100 kHz. A 16 kilowatt power amplifier is available for power testing of sonar projectors, although the relatively shallow water depth places a cavitation limit on the radiated power levels that can be achieved.

Acoustic Calibration Tank

The Acoustic Calibration Tank Facility, located at the main DRDC Atlantic site, is primarily used for calibration of hydrophones and other underwater acoustic transducers, whose size and frequency range are compatible with the tank’s dimensions. The freshwater tank is circular in cross section, 7.3 metres in diameter and 4.5 metres deep. It is build of redwood and lined with insulkrete and rubber to reduce reverberation. The dimensions are such that the tank’s operating frequency range is typically greater than 1 kHz, as limited by the computerized data collection and analysis system. Sonar transducers operating below 1 kHz are usually calibrated at the Acoustic Barge. The tank has a 0.5 tonne hoist for positioning heavier equipment and precision rotating stations that are used to measure transducer beam patterns. The tank is also used to test and evaluate other types of sea-going scientific apparatus and military equipment.

High Pressure Test Facility

DRDC Atlantic operates two pressure vessels for testing underwater sensor systems or components, such as transducers, cables and connectors, under hydrostatic loading that simulates great depths in the ocean. This is an important part of the evaluation of equipment that is designed for use in the undersea environment. The smaller pressure vessel is 12 cm in diameter and 45 cm in length with a maximum pressure rating of 34 MPa, equivalent to an ocean depth of 4 kilometres. The larger vessel is 90 cm in diameter and 2.4 metres in length and is rated for 58 MPa, equivalent to a depth of 6.8 kilometres.

Customers include DRDC Atlantic defence scientists, the Canadian Forces, other government departments and Canadian industry. Bookings for all of the facilities should be made well in advance. Customers are charged either an hourly or daily rate for use of the facilities.

Interior of the DRDC Atlantic Barge.

For more information

Manager/Technical Services
Phone: (902) 426-3100 ext. 143
E-mail:

Defence R&D Canada – Atlantic
P.O. Box 1012, Dartmouth, Nova Scotia B2Y 3Z7
Phone: (902) 426-3100 Fax: (902) 426-9654

www.atlantic.drdc-rddc.gc.ca
Fact Sheet No. TS0203
© DRDC Atlantic 2002

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