Abstract:
This thesis presents a method to measure leakage rate of gas through pipeline using Acoustic Emission (AE) techniques. Various sizes of steel pipe schedule 40 , ranging from one to
three inches, were used and tested with pipe-inlet pressure of range from 0 to 80 psi. Leakage rates through artificial leak source was measured by calculating the pressure difference
within the chamber and compared to AE technique. We found that the source mechanism generating AE signal in a leaking pipe was the decay of turbulence from fluid flow at the
leaking area. In our experiment, we found that AE technique had high sensitivity to detect leakage signal. Typically, these signals were continuous AE signal and were converted to a set
of AE parameters. The most signal used AE parameters which is the Average Signal Level (ASL) was employed in this work. The AE parameter exhibited high correlation with the leakage
rates, pipe sizes and inlet pressures. Minitab program was used to analyze the correlation and to from an equation in order to predict the leakage rate. Our experiments showed that the error
of the leakage rates from the equations was compared with the leakage rates from the chamber was in variation of 5.14 - 63.06 %. Beside, AE can find leakage location by using Cross
Correlation technique which detects sound wave caused by leakage moving towards the sensor head, then calculate the difference approach time to find the location. The detection resulted
in error variation of 1.15  47.8 %.