Development Of Pressure-Gradient Acoustic Vector Sensors - Video Portal
Development Of Pressure-Gradient Acoustic Vector Sensors
LTJG Ahmet Serkan Yilmaz, Turkish Navy
Abstract: Acoustic vector sensors yield the direction of a plane wave, and can be used in determining the direction to a source without the need of an aperture of phase-coherent sensors. We investigate two types of sensors which can determine the direction of an incoming plane wave to 180°. The first involves measurement of the difference voltage of two side-by-side pressure sensors that are ideally identical. We compare theoretical calculations to measurements in air in an anechoic chamber. We observe significant experimental deviations, which are shown to result from nonuniformities of the sound field due to the chamber, and the fact that the sensitivities of the individual pressure sensors are not identical. Two different lecture demonstrations of this type of pressure-gradient sensor are investigated: one in an open environment of a classroom, and one in a standing wave tube. Finally, we overcome the problems of the measurement of the difference voltage of two pressure sensors by considering a second type of pressure-gradient sensor that consists of a piezoelectric sheet of metalized polyvinylidene fluoride (PVDF) sandwiched between two open-ended cylinders. We show that this sensor is a promising new type of pressure-gradient transducer that can be adapted for underwater use.