A Nearfield Acoustic Holography-Based Method for Measuring the Sensitivity of a Particle Velocity Sensor

Unlike the pressure sensor (p-sensor), the sensitivity of the particle velocity sensor (u-sensor) of a pressure-velocity (p-u) sound intensity probe is rather difficult to obtain because the standard reference particle velocity sensor is not available. Usually the sensitivity of the u-sensor is obtained by exposing the probe to a sound field where the acoustic impedance has a closed-form solution. This paper develops a nearfield acoustic holography (NAH)-based method to measure the sensitivity of the u-sensor, in which the acoustic impedance is reconstructed from the measured pressure and particle velocity, and therefore the proposed method is still applicable when the acoustic impedance does not have a closed-form solution. The feasibility of the proposed method was examined through two experiments with two sound sources: a dodecahedron source and a loudspeaker. The results show that the sensitivity obtained by using the proposed method agrees well with that given in the calibration report provided by the manufacturer.