A new Leak Detection Method Applicable for Low and High Pressure Vessels

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Ahadi, Majid | 2014

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Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 46216 (05)
University: Sharif University of Technology
Department: Electrical Engineering
Advisor(s): Sharif Bakhtiar, Mehrdad
Abstract:
A New method is proposed to find a mother wavelet for the best localization of acoustic emission (AE) signals generated by leakage in a pipe. At the first step, knowing stochastic nature of acoustic emission signals, a leakage signal in time domain was trapped by monitoring the Short Time Fourier transform (STFT) of AE signal over a relatively long time interval to find frequency traces of leakage AE signal. The trapped signal was used to find a mother wavelet for the best signal localization. Then a novel method for AE signal detection using tuned wavelet is discussed. For this purpose experiments were done in predefined situations to collect signals generated in water filled plastic pipe to identify leakage signals and background noises such as signals related to the pipe modals, splash and interference noises. The results indicate that tuned wavelet could identify occurrence time of an AE event precisely. Also sources of signal and related signal energy due to leakage could be recognized as well
Keywords:
Sound Waves ; Wavelet Transform ; Short Time Fourier Transform ; Oil Tanks ; Gas Reservoirs ; Leakage ; Pipe Leakage

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