Passive cavitation detector
A type of hydrophone specifically designed to provide optimum signal to noise ratio in the measurement of cavitation induced acoustic signals.
Overview
Cavitation is often induced by an external acoustic field which typically have very high acoustic amplitudes but the acoustic emissions from these cavitation events are significantly smaller. The small acoustic emissions are characterised by well defined spectral peaks at integer harmonics and sub harmonics relative to the fundamental bubble frequency.
Passive cavitation detectors have a centre frequency of at least 3 times higher than the drive signal. This ensures that the high amplitude drive signal is filtered out whilst the acoustic emission of the cavitation event can be measured.
