B Milhomem Thiago Antônio, Defilippo Soares Zemar M, Musafir Ricardo E, Müller Swen
Laboratory of Electroacoustics, Acoustics and Vibration Metrology Division, Scientific and Technology Metrology, National Institute of Metrology, Quality and Technology, Avenida Nossa Senhora das Graças, 50, Prédio 1, Xerém, Duque de Caxias, Rio de Janeiro, 25.250-020, Brazil.
Department of Mechanical Engineering, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, 21.941-972, C.P. 68.503, Brazil.
J Acoust Soc Am. 2018 Jun;143(6):3658. doi: 10.1121/1.5043395.
This paper presents a procedure for diffuse-field calibration of half-inch laboratory standard microphones by reciprocity using three microphones and a small reverberation chamber. The procedure consists of obtaining the impulse response of the system microphone-chamber-microphone and employing it to determine both the electrical transfer impedance between the microphones and the chamber's reverberation time (necessary to calculate the acoustic transfer impedance between the microphones). The electrical transfer impedance is calculated from the reverberant part of the obtained impulse response and the reverberation time is obtained by integrating the same impulse response. A comparison between results obtained by the proposed procedure (by the reciprocity method) and pressure field results corrected to diffuse-field (an usual alternative method) shows the accuracy of the proposal, while a comparison with other diffuse-field procedures using the reciprocity method shows that the measured frequency range is extended down, whereas similar performance is found in the common range.
本文介绍了一种使用三个麦克风和一个小型混响室通过互易法对半英寸实验室标准麦克风进行扩散场校准的程序。该程序包括获取系统（麦克风 - 混响室 - 麦克风）的脉冲响应，并利用它来确定麦克风之间的电传输阻抗以及混响室的混响时间（计算麦克风之间的声传输阻抗所必需的）。电传输阻抗由所获得脉冲响应的混响部分计算得出，混响时间则通过对同一脉冲响应进行积分得到。将所提出的程序（通过互易法）得到的结果与校正为扩散场的压力场结果（一种常用的替代方法）进行比较，显示了该提议的准确性，而与使用互易法的其他扩散场程序进行比较表明，测量频率范围向下扩展，而在共同范围内发现了类似的性能。
