Abstract: The characteristics of acoustic signal for pipe leakage and general wavelet primary function were analyzed. It concludes that the suitable primary functions for acoustic signal of pipe leakage are Daubechies wavelet and Symlet wavelet. The experiments of the acoustic inspection were conducted in water leakage of the carbon steel pipe and the wavelet transform of the leakage signal was done by db5 and sym5 wavelet. It shows that the most energy is a6 level signal energy and the peak frequency of the signal focus on 2.90~3.81 kHz. The maximum relative error of two different wavelet transforms is 0.77% in the energy analysis and 5.17% in frequency analysis.

Key words: Acoustic     ,  ,  Wavelet transform  ,   , Leakage  ,   ,  Frequency

摘要： 对管道泄漏声发射信号特点和常用小波基函数特点进行了分析,指出Daubechies小波和Symlet小波
是较适于泄漏声发射信号处理的基函数。进行了碳钢管道水泄漏声发射检测实验,用db5和sym5两种小波基分别
对泄漏信号进行小波变换,结果表明,a6级信号的能量占总能量的绝大部分,信号峰值频率集中在2.90~3.81kHz,
两种小波变换在能量分析中最大相对偏差为0.77%,在频率分析中最大相对偏差为5.17%。

关键词: 声发射 ,     小波变换   ,   , 泄漏  ,  ,  频率