GB/T 17248.4-1998 in English

《GB/T 17248.4-1998声学 机器和设备发射的噪声 由声功率级确定工作位置和其他指定位置的发射声压级》由TC17（全国声学标准化技术委员会）归口，主管部门为中国科学院。
本标准规定了根据声功率级计算确定在机器设备附近工作位置或指定位置上，机器设备所发射声压级的两种方法。其主要目的是在给定的环境条件和规定安装、运行工况条件下，对相同类型但不同规格的机器设备噪声性能进行比较，所得结果可以用来表示和验证ISO 4871所规定的发射声压级。

Scope

This standard specifies two methods for calculating and determining the sound pressure level emitted by machinery and equipment at the working position or designated position near the machinery and equipment based on the sound power level. Its main purpose is to compare the noise performance of machinery and equipment of the same type but with different specifications under given environmental conditions and specified installation and operating conditions. The results obtained can be used to represent and verify the emission sound pressure level specified in ISO4871 . The determination of emission sound pressure level shall adopt the same frequency and time weighting, or the same frequency band as the test of sound power level. NOTE 1 See Table 1 of ISO 11200:1995 for a summary of international standards related to the above. 2 The emission sound pressure level determined by this standard for the machine is generally lower than the sound pressure level measured directly when the machine is actually running in the factory at any given position and under the specified installation and operating conditions. This is because the scene is affected by other machines and sound field conditions, and ISO11690-3 provides a method for calculating the emitted sound pressure level of a single machine operating in a studio. Generally speaking, the resulting difference should be between 1 and 5dB, and the difference is even greater in special cases. This standard applies to all kinds of machines, fixed or not, indoor or outdoor, especially mass-produced machines. However, the method of this standard is not applicable to outdoor strong directional sound sources. This standard is especially applicable to machines whose length, width and height are all less than or equal to 1m. Some cases also apply to larger machines (see 6.2.3). This standard applies to all types involved in the noise sound power level test methods in GB/T14259 and ISO12001.