Measurement at simulated ocean conditions

Characterising transducers and materials

The NPL Acoustic Pressure Vessel (APV) enables free-field testing under simulated ocean conditions, providing much greater environmental control and a cost-effective alternative to sea trials. It may be used for characterisation of acoustic transducers and systems as a function of temperature and depth.

Our capability includes:

• Simulation of ocean depths of up to 687 m [6,895 kPa or 1000 psi]
• Water temperature may be controlled within the range 2 ºC to 35 ºC
• Operating acoustic frequencies from a few kHz to 450 kHz 
• Two access ports – large port is 0.84 m in diameter
• Rotator shaft allowing rotation of devices weighing up to 350 kg

Materials testing

NPL has developed the capability for testing of the performance of materials used in underwater acoustics. Such materials are used as acoustic windows, sonar domes and acoustic absorbers. The test samples are in the form of panels of maximum dimensions 800 mm wide by 900 mm high.

We can determine insertion loss (transmission loss) and echo reduction (reflection loss) in the frequency range from 1 kHz to 100 kHz and over a range of environmental conditions of (water temperature of 2 ºC to 35 ºC and hydrostatic pressures of up to 2.4 MPa).

Find out more about NPL's Acoustic tests in simulated ocean conditions service

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