SONDA PER CORRENTI PARASSITE CON DISCRIMINAZIONE FRA DIFETTI E RUMORE

摘要

Eddy current probes which are used to internally or externally inspect cylindrical components for localized defects have a main coil arrangement that induces and senses eddy current in the components. In accordance with the present invention, the probe further includes an element associated with the main coil arrangement to generate a detected defect signal distinct from a detected noise signal. The element can include one or more further coils mounted coaxially with the main coil arrangement so as to be between the main coil arrangement and the component to be inspected. The element may alternately be a cylindrical conductive sleeve mounted coaxially with the main coil arrangement so as to partially shield the coil arrangement from the component to be inspected. An electrical phase shifting network may be connected to the one or more further coils to enhance the distinction between the signals.