摘要
1 工作原理及整机性能泄漏超声波本质上是湍流及冲击噪声。泄漏驻点压力P与泄漏孔口直径D决定了湍流噪声的声压级L。著名学者马大猷教授推出如下基本公式: 式中,L为喷注垂直方向距喷口1 m处的声压级(单位:dB);D为喷口直径(单位:mm);D_0=1 mm;P_0为环境大气绝对压力;P为泄漏孔驻压。图1为泄漏口不规则时的噪声频谱图。实验驻压P_1=4.7 kg/cm^2,测量位置θ=180°。
This paper describes the principle, property, measurd results and some examples of the ultrasonic leak detector developed by the authors. The working frequency, which is then converted into audible sounds, of the apparatus is (42～44) kHz, the probe's directivity is 20 degrees, the sensitivity is 60.9mV/Pa and the input noise 0.03nV. It's signal-noise ratio is 4 times higher than that of the model 4905A made by HP company in optimum gain. Even when intense audible noise is present, the instrument can detect and locate the leaks in pressure and vacuum systems, the points of mechanical friction and high-voltage arcs.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
1989年第6期114-117,共4页
Journal of Southeast University：Natural Science Edition
关键词
超声检漏仪
工作原理
piezoelectric ceramic transducer, ultrasonic tests, instrument
