Research On The Reciprocity Calibration Of Hydrophone In A Diffuse Sound Field Based On A Small Water Tank

The receiver sensitivity parameter of the hydrophone is one of the important indexes to characterize the acoustic performance of the hydrophone.It is responsible for the transmission of the underwater sound pressure.Therefore,in the field of water measurement and testing is very concerned about the hydrophone receiver sensitivity calibration method and calibration system.Conventional hydrophone sensitivity calibration methods are generally carried out in the free field,demanding high free field conditions for the measurement space,and therefore require the construction of large muffled or non-silencing ponds.However,with the decrease of the test frequency,in the silencer pool due to the influence of boundary reflection,the use of pulse signal can not be direct wave and reflected wave separation,and gradually form a reverberant sound field.Therefore,the method of calibrating the hydrophone in the reverberation field is studied.On this basis,the calibration method and calibration of the calibrated hydrophone are put forward by using the reciprocity method in the small tank reverberation field to ensure the measurement accuracy.System,the method of measuring space sound field conditions are not demanding,especially suitable for the measurement of water sensors for calibration,is a simple measurement of space structure,convenient and practical laboratory hydrophone calibration method.Based on the study of the theory of reverberation field and the method of reciprocity calibration,the paper first designs and develops the reverberant water tank and 12 reciprocating transducers.At the same time,the distribution characteristics of the sound field of the small water tank and the reciprocating transducer Impedance characteristics,linearity and reciprocity were tested.Secondly,the sensitivity of Reson TC4035 and B&K8104 sound pressure hydrophone and self-developed vector hydrophone was tested.The test results showed that:(1)The reverberant tank designed by 5kHz-50 kHz frequency range,the use of reciprocity method for sound pressure hydrophone sensitivity calibration,calibration results and its free field calibration results are basically consistent;(2)the sensitivity of the vector hydrophone can be 5kHz~20kHz frequency Finally,the measurement uncertainty of the reverberation field reciprocal calibration method is analyzed,and the expansion uncertainty of the method is 1.26 dB,and the calibration uncertainty is 1.26 dB,which is the same as the result of the calibration in the free field.In the hydrophone sensitivity free field two comparison calibration method of uncertainty,with a high calibration accuracy.