ISO 5136规定了一种用于测试管道风扇和其他空气移动设备的方法，以确定辐射到设备入口和/或出口侧上的消声终止管道中的声功率。 该方法适用于发出稳定、宽带、窄带和离散频率声音的风扇，以及空气温度在-50℃至+70℃之间。测试管道直径范围为0.15米至2米。小型（d<0.15 m）和大型（d>2 m）测试管道的测试方法分别在资料性附录H和I中描述。 该方法适用的麦克风头处的最大平均流速取决于所使用的麦克风屏蔽的类型，如下所示: 泡沫球15米/秒；鼻锥20米/秒；取样管40 m/s。 高于这些值，麦克风屏蔽件对湍流压力波动的抑制可能是不充分的。ISO 5136中描述的方法适用于其中风扇在至少一侧上连接到管道的声源。它也适用于其他风扇/衰减器组合或包含风扇的设备，其可以被认为是“黑匣子”。 ISO 5136涵盖的风扇和其他设备的例子有 管道离心风机、管道轴流风机、管道混流风机、管道空气处理机组、管道除尘机组、管道空调机组和管道炉。 ISO 5136也适用于其他空气动力学源，例如箱、阻尼器和节流装置，条件是由辅助风扇输送的安静气流是可用的，并且测试管道中的声压与湍流压力波动的信噪比至少为6dB。 不适用于非管道风机或设备。

ISO 5136 specifies a method for testing ducted fans and other air-moving devices to determine the sound power radiated into an anechoically terminated duct on the inlet and/or outlet side of the equipment. The method is applicable to fans which emit steady, broad-band, narrow-band and discrete-frequency sound and to air temperatures between - 50 °C and + 70 °C. The test duct diameter range is from 0,15 m to 2 m. Test methods for small (d < 0,15 m) and large (d > 2 m) test ducts are described in the informative annexes H and I, respectively. The maximum mean flow velocity at the microphone head for which the method is suitable, depends on the type of microphone shield used, and is as follows: foam ball 15 m/s; nose cone 20 m/s; sampling tube 40 m/s. Above these values the suppression of turbulent pressure fluctuations by the microphone shield may be insufficient. The method described in ISO 5136 is applicable to a sound source in which a fan is connected to ducts on at least one side. It is also applicable to other fan/attenuator combinations or equipment incorporating fans which can be considered as "black boxes". Examples of fans and other equipment covered by ISO 5136 are ducted centrifugal fans, ducted axial flow fans, ducted mixed-flow fans, ducted air-handling units, ducted dust-collection units, ducted air-conditioning units, and ducted furnaces. ISO 5136 is also applicable to other aerodynamic sources such as boxes, dampers and throttle devices provided that a quiet air flow delivered by an auxiliary fan is available, and the signal-to-noise ratio of sound pressures to turbulent pressure fluctuations in the test duct is at least 6 dB. It is not applicable to non-ducted fans or equipment.