ISO 10534-2:2023 声学 阻抗管中声学特性的测定 第2部分：法向吸声系数和法向表面阻抗的双传声器技术

标准编号：ISO 10534-2:2023

中文名称：声学 阻抗管中声学特性的测定 第2部分：法向吸声系数和法向表面阻抗的双传声器技术

英文名称：Acoustics — Determination of acoustic properties in impedance tubes — Part 2: Two-microphone technique for normal sound absorption coefficient and normal surface impedance

发布日期：2023-10

标准范围

本测试方法包括使用阻抗管、两个麦克风位置和频率分析系统来确定吸声材料对正入射声入射的吸声系数。它还可用于测定吸声材料的声表面阻抗或表面导纳。作为扩展，它还可用于评估均匀声学材料的固有特性，如其特性阻抗、特性波数、动态质量密度和动态体积模量。试验方法与ISO规定的试验方法相似？10534-1，因为它使用阻抗管，声源连接到一端，测试样品安装在管的另一端。然而，测量技术是不同的。在该测试方法中，由声源在管中产生平面波，通过使用壁挂式传声器或管内横向传声器测量两个固定位置的声压，并随后计算上一段中报告的复声传递函数和量来实现干扰场的分解。该测试方法旨在提供一种替代的、通常比？伊索？10534-1.来自阻抗管测量的法向入射吸收系数不能与根据ISO在混响室中测量的随机入射吸收系数相比较？354.混响室法将（在理想条件下）确定漫射声入射的吸声系数。然而，混响室方法需要相当大的试样。阻抗管方法仅限于法向和平面入射的研究，并且需要与阻抗管横截面尺寸相同的测试对象样品。对于仅发生局部反应的材料，漫射入射吸声系数可由阻抗管法获得的测量结果估算（见附录？E）。

This test method covers the use of an impedance tube, two microphone locations and a frequency analysis system for the determination of the sound absorption coefficient of sound absorbing materials for normal incidence sound incidence. It can also be applied for the determination of the acoustical surface impedance or surface admittance of sound absorbing materials. As an extension, it can also be used to assess intrinsic properties of homogeneous acoustical materials such as their characteristic impedance, characteristic wavenumber, dynamic mass density and dynamic bulk modulus.

The test method is similar to the test method specified in ISO 10534-1 in that it uses an impedance tube with a sound source connected to one end and the test sample mounted in the tube at the other end. However, the measurement technique is different. In this test method, plane waves are generated in a tube by a sound source, and the decomposition of the interference field is achieved by the measurement of acoustic pressures at two fixed locations using wall-mounted microphones or an in-tube traversing microphone, and subsequent calculation of the complex acoustic transfer function and quantities reported in the previous paragraph. The test method is intended to provide an alternative, and generally much faster, measurement technique than that of ISO 10534-1.

Normal incidence absorption coefficients coming from impedance tube measurements are not comparable with random incidence absorption coefficients measured in reverberation rooms according to ISO 354. The reverberation room method will (under ideal conditions) determine the sound absorption coefficient for diffuse sound incidence. However, the reverberation room method requires test specimens which are rather large. The impedance tube method is limited to studies at normal and plane incidence and requires samples of the test object which are of the same size as the cross-section of the impedance tube. For materials that are locally reacting only, diffuse incidence sound absorption coefficients can be estimated from measurement results obtained by the impedance tube method (see Annex E).

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