Patents Assigned to Her Majesty the Queen as represented by the Minister of National Defence in right of Canada
  • Patent number: 6344741
    Abstract: A method for the detection and the characterization of corrosion in multi-layer metallic structures using a pulsed eddy current technique. For this technique, a coil (or coils) is used both as field source (driven by a square wave voltage-controlled excitation), and/or as field sensor (measuring a transient response). The field sensor allows the capture of information about the condition of the area of the structure under inspection. The ability of this technique to detect corrosion hinges on the use of a transient response feature (i.e., Lift-off Point of Intersection) to infer the presence of material loss. With the help of a calibration standard, the Lift-off Point of Intersection provides the ability to quantify material loss in multi-layered structures. The results obtained with this method are independent of lift-off variations inherent to field inspections (i.e., changes in distance between the transducer and test object).
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: February 5, 2002
    Assignee: Her Majesty the Queen as represented by the Minister of National Defence in right of Canada
    Inventors: Sylvain Giguere, Stéphane J. M. Dubois