Method of locating and determining the intensity of a stress wave source

The loose part becomes the source of stress waves which on the external surface of the equipment are recorded and evaluated. The shape is compared of the spectral density function of the recorded signal at set time intervals and the ratio of values of the spectral density function in the frequency range of a 0.8 -1.2 multiple of the eigenfrequency of the probe with the values of this function in frequency ranges below the value of the eigenfrequency of the installed probe. This allows, eg., to locate loose parts in the steam generator primary water inlet collector. (J.B.)