VINCENT OGBONNAH ISRN:BTH-AMT-EX-2007/D-14--SE, pp. 68. TEK/avd. för maskinteknik, 2007.
Acoustic emission (AE) is an efficient non destructive testing technique for the diagnosis of machine health used in this thesis. The thesis involves using the recorded experimental data obtained from Acoustic emission signals to show how changes over time of different characteristics of acoustics emissions can be used as diagnostic measures of pitting damages on gear teeth. Analysis was done by using wavelet method, presenting results for changes over time in statistical properties of amplitude, frequency change and corresponding energy change. A linear relationship between acoustic emission, gearbox running time and pitting progression was established.