A Method for Small Leak Precise Location in Pressure Piping by Acoustic Emission

Due to leak location of acoustic emission (AE) signal affected by the surrounding noise and the signal with the dispersion and multimode characteristics in communication channels in pipeline, it is not accurate to use traditional AE technique for leak location. In this paper, scale analysis of AE signal de-noising by wavelet and the wavelet scales for selected db1, the horizontal level, is six layers. The continuous wavelet transform is used to analyze AE signal at time frequency and combined with modal acoustic emission (MAE) technique to reduce the impact of dispersion characteristics in signals. Finally, the exact position of the leak source is calculated by using the one-dimensional linear located formula. The experiment proved effectiveness of the method, making the positioning error of about 4%.