ISO 13347-4:2004适用于ISO 5801和ISO 13349中定义的工业风扇。它仅限于确定指定设置的空气声发射。未测量振动，也未确定空气声发射对振动影响的灵敏度。 可根据ISO 13347-4:2004进行测试的风机尺寸仅受测试装置的实际方面的限制。 ISO 13347-4:2004通过在封闭声源的测量表面上使用声强测量来确定声功率。 它提供了有关声环境、环境噪声、测量表面和测量次数的指南。测试装置通常设计为代表按照ISO 5801安装的风扇的物理方向，也用于ISO 13347-2。

ISO 13347-4:2004 applies to industrial fans as defined in ISO 5801 and ISO 13349. It is limited to the determination of airborne sound emission for the specified set-ups. Vibration is not measured, nor is the sensitivity of airborne sound emission to vibration effects determined. The sizes of the fan, which can be tested in accordance with ISO 13347-4:2004, are limited only by the practical aspects of the test installations. ISO 13347-4:2004 determines sound power by using sound intensity measurements on a measurement surface which encloses the sound source. It provides guidelines on the acoustical environment, ambient noise, measurement surface, and number of measurements. The test set-ups are generally designed to represent the physical orientation of a fan installed in accordance with ISO 5801 and also used in ISO 13347-2.