Acoustic Absorption Materials

[ewanb]

I am currently doing a project in which I measure acoustic levels in a test tank using a hydrophone, and possibly develop the system for offshore applications. The hydrophone chosen will be connected to a beacon housing and have as near as possible 360 degree vision and has a frequency range of 1 Hz to 100 kHz. So that acoustic waves are not reflected back off the housing affecting the hydrophone's readings it is thought a conical shaped end cap made of an acoustic absorbing material could be used to absorb these.

I would like to know if any one knows any suitable materials for this application and who manufactures them?

Cheers

 

[Rob45]

Not likely you'll find an absorber good down to 1 Hz, nor even for that matter much below 1 KHz, for reasons too complex to detail here.

You'd be better off developing an algorithm to deal with any reflections off the housing that do occur.

 

[GregLocock]

Or use two mics and measure intensity.

Cheers

Greg Locock