The Pipeline Leakage Point Location System And Experimental Research Based On Virtual Instrument Technology

This paper proposes one set of leakage point location system based on the correlation analysis, through the virtual instrument technology. We choose the water sound signals as the studying object when the pipelines leak out, carry out the orientation task via the Fast Fourier Transform. The theory of acoustic emission principle, fast Fourier transform, cross correlation were introduced; at the same time, the system correlation hardware, including sensors, amplifiers, analog filters and computer as the upper machine were introduced too.The former channels were redesigned based on referring a lot of literature and experiments. The former channels contain sensors, amplifiers and analog filters. They were improved absolutely right through the experimental testing.This paper use PCI-1716L data acquisition card made by Advantech Company, to collect acoustic emission signal data, and transform the analog signal to digital signal. PCI-1716L is a card with 16-bit, 250kS/s high-resolution multifunction and w/o analog output. It includes DAQ LabVIEW driver which is very convenient. The software was programmed by LabVIEW(Laboratory Virtual Instrument Engineering Workbench). LabVIEW saves a lot of programming time, but its velocity is really fast. It's a good programming language provided for scientists and engineers.The digital filter and analog filter were both employed in the test, the ability and sensitivity of the digital signal processing were strengthened.In the test, according to the difference of signal condition, the correlation function of two-way signals as for the ideal signal and the actual signal were evaluated separately. Thus, realize the pipeline leakage point localization. Finally, carry on the basic analysis and the comparison as for each kind of test result.