Abstract Abstract：To address the low-frequency reciprocity calibration in coupled cavities under variable pressure conditions, the influence of changing pressure on the low-frequency calibration in cavities is explored through a combination of theoretical calculations, Comsol acoustic field simulations, and experiments. We analyze the reciprocity principle of low-frequency calibration of the coupled cavity and the characteristics of the acoustic field in the cavity by theory, derive the calibration formula for the reciprocity constant, and show the influence of the distribution structure of the transducer in the cavity on the acoustic field under the state of the original liquid-cavity by Comsol simulation, and calculate the correction factor by the acoustic field distribution, and compensate for the low-frequency reciprocity calibration formula of the coupled cavity, and the results show that the change of the transducer's position in the cavity affects the calibration theoretical system, and the increase of frequency affects the low-frequency calibration of the cavity. The results show that the change of the position of the transducer in the cavity will affect the calibration theoretical system, and the frequency increase will affect the sound field distribution in the cavity even more, and the correction factor of 1-1100Hz band is added to the measured reciprocity constant, and the optimization scheme of the correction factor of the coupling cavity is explored by the variable pressure experiment of the cavity from atmospheric pressure to 4MPa, combined with the simulation, and the experimental results show that the maximum difference in the sensitivity of calibration using the correction factor (bit-shape coefficient) is 1.1dB, and the average standard deviation is 0.29 dB.
WANG Ming-Wei,WANG Yue-Bing,ZHAO Peng. Sensitivity compensation analysis of coupled cavity reciprocity method under variable voltage conditions[J]. , 2025, 46(3): 405-411.
2025, Vol. 46 
