扫描声强法声功率测量的扫描路径误差分析

以单极子、偶极子及四极子声源为例，建立了矩形测量面上三种扫描路径（方波、锯齿波、直线加半圆）的误差函数数学模型；在扫描速度恒定的条件下，得出各路径及声源对扫描线的误差分布函数图形。结果显示：锯齿波误差最小；声强标准推荐的直线加半圆路径误差略大于方波；无指向性声源各扫描路径均误差较小（单极子源），对于指向性声源，扫描路径的形式对测量精度的影响较大。

Analysis of Errors due to Scanning Paths in Sound Power Measurement Using Scanning Intensity Method

The error functions of scanning paths in sound power measurement on square surface due to monopole, dipole and quadrupole sources are developed. The error curves of different paths and sources vs scanning line number m are obtained. The results show that the minimum error can be obtained along the path of sawtooth pattern. The error along a linear line plus a semicircle pattern path which is recommended in ISO9614-2 is a little greater than that along square wave path. If directivity factor of sound source is equal to 1, the errors along different paths are almost the same. Otherwise the scanning path pattern can greatly affect the estimation accuracy of sound power measurement.