Method for wall thickness measurement of a hollow blade

摘要

Method in which Eddy currents are applied using two poles of a detector (4) magnetic core. The currents applied are perpendicular to the wall (2) surface, i.e. parallel to support frames (3) behind the wall. The poles have coils connected in series with the wall thickness determined by displacement of the probe over the surface. The probe is pre-calibrated on a wall without supports and a software system is used to correct the results obtained for the effect of the sub-surface frames.