INSPECTING AN OBJECT OF ELECTRICALLY CONDUCTING MATERIAL

摘要

A method of inspecting an electrically conductive object (2) so as to detect the presence of an anomaly (15, 20) using a probe (4) comprising a transmitt er coil (6) and a receiver coil (8), which method comprises the steps of: (a) selecting a set of points on the near surface (12) of the object (2) that ar e to be inspected;(b) selecting a first inspection point from the set; (c) positioning the probe (4) at the selected inspection point, inducing eddy currents in the object and determining a characteristic value, .PHI., of the electromagnetic field generated by the eddy currents;(d) selecting a next inspection point from the set and repeating step (c) until all inspection points have had their turn; and(e) inferring that an anomaly is present at a n inspection point if the characteristic value .PHI. differs significantly fro m a norm.