平面波耦合腔中热传导和声泄漏对低频互易校准的影响  

The Impact to the Low-frequency Reciprocity Calibration Caused by Heat Conduction and Sound Leakage in the Coupler

作　　者：裘剑敏[1] 何龙标[2] 许欢[2] 钟波[2] 牛锋[2] 

机构地区：[1]浙江省计量科学研究院,浙江杭州310013 [2]中国计量科学研究院,北京100013

出　　处：《计量学报》2013年第5期461-465,共5页Acta Metrologica Sinica

摘　　要：针对低频耦合腔互易校准中存在的热传导和声泄漏问题，通过理论计算和不同长度耦合腔的系列实验研究，探讨其对互易校准结果的影响规律。首先阐述了互易校准原理及电容传声器低频时的频响特征，传声器均压孔在声场外时，低频声压灵敏度随着频率降低而逐渐增加；其次，对发射传声器-耦合腔一接收传声器构成的耦合腔系统中的热传导修正因子进行计算，结果表明，随着耦合腔长度变长，热传导修正因子变小，不确定度分量变小；通过不同长度的耦合腔组成的互易校准系统研究声泄漏的影响并探讨其优化方案，实验结果表明，10mm和15mm耦合腔对互易校准结果影响较小，重复性高，该实验结果与传声器的低频响应特性一致。The effect of heat conduction and sound leakage in the coupler on the low-frequency reciprocity calibration was discussed. The theoretical calculations and the experiments with different lengths of the couplers were implemented to find the rules. First by the principle of the reciprocity calibration and the frequency response characteristics of the condenser microphones in low frequency was described. The sound pressure sensitivity gradually increased as the frequency decreased, and the heat conduction correction factor in the coupled system by the excited microphone - coupler - received microphone become smaller when the lengths of the couplers turned to longer, and the uncertainty components become smaller. Different lengths of the couplers were used to study the impaction of the sound leakage and the optimization program was explored . The experimental results showed that, with 10ram and 15mm couplers the leakage had smaller impaction and the sensitivity had high reproducibility. At the same time, the experimental results conformed the low frequency response characteristics of the condenser microphones in low frequencies.

关 键 词：计量学 互易校准 声压 平面波耦合腔 热传导 声泄漏 

分 类 号：TB95[一般工业技术—计量学]