GB/T 17248.2-1999
声学 机器和设备发射的噪声工作位置和其他指定位置发射声压级的测量 一个反射面上方近似自由场的工程法
Acoustics--Noise emitted by machinery and equipment--Measurement of emission sound pressure levels at a work station and at other specified positions--Engineering method in an essentially free field over a reflecting plane