Applications of vector hydrophone in underwater sound absorption coefficient measurement are discussed. Vector hydrophone composed of pressure sensor and particle velocity sensor is capable of measuring the pressure and particle velocity synchronously. With the Pressure-Velocity (P·V) method based on estimate of sound energy and sound energy density, characteristic impedance and absorption coefficient are obtained. The P·V method employed in water-filled impedance tube is regarded as a substitute of the two-hydrophone method. P·V method abandons the uncertainty generated by the transfer function and the distance between two sensors. P·V method employed in free field reduces the effect of conventional parameters such as diffraction. The uncertainty analysis of the P·V method is also presented. As a substitute of two-hydrophone method, the main uncertainty is generated by the phase response between the pressure and velocity sensor which can be well calibrated by the manufacture. Employed in free field measurement, P·V method based on vector measurement technology can efficiently abandon the effect of diffraction. A numerical perturbation method is employed in the uncertainty analysis of the pressure P, particle velocity V and the phase response difference between P and V.
展开▼
