非刚性管中换能器灵敏度的测量方法研究

Study on the Measurement Method of Transducer Sensitivity in Non-rigid Tube

为实现非刚性管中的换能器低频灵敏度校准,提出了基于互易常数修正的管中灵敏度校准方法。首先,基于管中非刚性边界条件和声压的方程进行了互易常数的推导及修正,并围绕管中互易常数的修正开展了仿真分析,得到测量频率段互易常数的修正值;其次,搭建实验系统开展了基于互易法的管中换能器的灵敏度测量研究。研究表明,管中互易常数的修正使互易换能器灵敏度值更加接近自由场互易法测得的灵敏度值。在0.5~4 kHz频率范围,补偿后的互易换能器灵敏度级最大起伏为-1.41 dB,极大改善了未修正的测量情况,与自由场测量值的误差较小,符合声学计量要求。通过对实验与仿真进行对比分析,验证了该方法的有效性和准确性。

In order to realize the low-frequency sensitivity calibration of the transducer in a non-rigid tube,a sensitivity calibration method based on the correction of the reciprocity constant in the tube is proposed.Firstly,the derivation and correction of the reciprocity constant based on the non-rigid boundary conditions and the equation of acoustic pressure in the tube,and the simulation analysis of the correction of the reciprocity constant in the tube,and the correction of the reciprocity constant in the measurement frequency band are obtained;secondly,the experimental system is built to carry out the sensitivity measurement of the transducer in the tube based on the reciprocity method.The study shows that the correction of the reciprocity constant in the tube makes the sensitivity value of the reciprocal transducer closer to the sensitivity value measured by the free-field comparison method.In the frequency range from 0.5 to 4 kHz,the compensated reciprocal transducer sensitivity level has a maximum undulation of-1.41 dB,which greatly improves the uncorrected measurement situation and has a small error with the free field measurements,meeting the acoustic metrology requirements.The results verify the validity and accuracy of the method through comparative analysis of experiments and simulations.