Reciprocity calibration of underwater acoustic transducer in a reverberation pool

Abstract

A new underwater acoustic transducer reciprocity calibration method was put forward in this paper. This calibration was finished by the space-averaging in the reverberation pool, and the influence of normal mode interference was eliminated, so the reverberation field acoustic parameters were obtained in the reverberation pool. The calibration can be set up in a small reverberation pool. In the case of the same frequency range acoustic transducer calibration, the reverberation pool for reverberation method reciprocity calibration can be smaller than the free-field pool for free-field reciprocity calibration. The reverberation field reciprocity constant was determined by measuring the reverberation time, the single-frequency sine signal was emission by the sound source higher than the cutoff frequency, the transmitting transducer and receiving transducer was space-averaged in the area of the reverberation, and the corresponding electrical parameters were obtained, so the receiving sensitivity for the reciprocity transducer and the testing hydrophone was calculated. The testing and the results of the reverberation calibration are presented in this paper. The error between the hydrophone calibration by the reverberation method and the factory free field calibration was less than 1.4 dB, and the A kind of measuring uncertainty is less than 0.13 dB. This method can be applied to all kinds of hydrophones and transducer calibration.