扫描速度对扫描声强法测量声功率精度的影响

Influence of scanning speed on sound power measurement precision in sound intensity scanning method

ISO9614-2或GB/T16404.2-1999标准都对用扫描声强法测量声功率时,声强探头的移动速度做出了规定,但范围较宽,难以选择。为了研究扫描速度对扫描声强法测量声功率精度的影响,以单极子、偶极子、四极子声源为例,建立了扫描声强法测量声功率误差的理论分析的数学模型,对模型的仿真曲线进行了分析,并且在半消声室进行了实验验证。2种方法研究结果表明,在各种扫描速度下均有:锯齿形扫描收敛速度最快,扫描速度大小对扫描声强法测量声功率精度的影响不大。为了提高测量效率,可以选择比标准规定更快的扫描速度。

The moving speed of sound intensity probe in sound power measurement using sound intensity scanning is prescribed in ISO 9614-2 or GB/T16404. 2-1999 standards, but the speed ranges are wide and difficult to choose. To study the influence of scanning speed on sound power measurement precision using sound intensity scanning, the monopole source, dipole source and quadrupole source were investigated, and the sound power measurement error analytic model was established. The simulation curves of the mathematical model were analyzed, and verified by the experiment carried out in a semi-anechoic chamber. The results for two experiment methods show that under various scanning speeds, the convergence speed of the saw-tooth scanning is the fastest, and the scanning speed has little influence on sound power measurement precision using sound intensity scanning. To improve measurement efficiency, a scanning speed faster than the standard one can be chosen.