Reserch On Leak Detection Of Pressure Pipeline

With the great development of economy, energy consumption becomes more and more important in our country. Environment pollution is now a great problem around us. Nautral gas is a good choice for this. Because of the danger of the natural gas, the safety of the natural gas pipeline is very important. In order to solve this problem we put forward an idea of collect multi-frequency leakage signal in ultrasonic frequency band when the pipeline leaks nautral gas. The device is designed to work in explosive environment without any problem.Ultrasonic detection of leakage is basically to get useful small signal in the yawp, and then amplify the signal effectively. In the analog circuit design, we firstly make use of sensor array to get the small signal. And we also use the JFET amplifer circuit to amplify the small singal. Then we uses the programable amplifer ISPPAC10 to amplify the signal and use the active filter to decrease the yawp. High speed DSP chip is TMS320F2812, which analyses the signal in time and frequency domain and makes the final decision. The realization of hardware and software of the DSP system is covered in this thesis. In order to get worthy result, we use two kinds of sensors to do the experiment, which are 40kHz sensor and 25KHz sensor.