数字化声学测量技术 Ⅱ.数字式声强及声功率测量系统

本文介绍在数字声学测量分析系统中，通过双传声器信号互谱密度的计算进行声强及声功率测量的基本原理。该数学分析系统由微计算机，数字信号处理卡和Ａ／Ｄ变换卡组成。在一个数字系统中，通过快速傅里叶变换（ＦＥＴ）进行互谱计算是十分有效的。本文着重介绍了，在声强的测量分析中对声强探头两传声器的固有相位差进行补偿的重要性和补偿方法，这是声强测量的重要环节。

Digital Acoustic Intensity and Sound Power Measuring system

This paper presents the measurement methods of acoustic intensity and sound power using the cross-spectral density of two microphones, in a digital acoustic signal analysis system. The systein consists of a microcomputer, a digital signal processing card and an A/D converter card. It is very efficient to get the cross-spectral density by the Fast Fourier Transform in this digital system, Compensation can be made to the phase difference between the two inicrophones of the intensity probe which is the key point to the sound intensity measurement.