Measurement of pressure on a surface using bubble acoustic resonances

Abstract

The frequency response of gas bubbles as a function of liquid ambient pressure was measured and compared with theory. A bubble size with equivalent spherical radius of 2.29 mm was used over a frequency range of 1000-1500 Hz. The ultimate aim is to develop an acoustic sensor that can measure static pressure and is sensitive to variations as small as a few kPa. The classical bubble resonance frequency is known to vary with ambient pressure. Experiments were conducted with a driven bubble in a pressurizable tank with a signal processing system designed to extract the resonant peak. Since the background response of the containing tank is significant, particularly near tank-modal resonances, it m..