ACOUSTIC-EMISSION SOURCE PARAMETERS IN COAL SAMPLES

Acoustic emission (AE) in coal samples during uniaxial loading were in vestigated. The displacements generated by AE waves reaching the side surface of a tested sample were recorded using a measuring system with flat frequency response. The measuring systems' quality made possible the determination of the basic properties of the AE sources directly from the characteristics of the registered AE pulses. The rise time an d the size of AE sources for different stages of failure of material t ested have been examined.