Abstract: A system for mapping a surface defect in an electrically-conducting material by measuring a change in the resonance of the material includes a flexible printed circuit board and a two dimensional array of transducers printed on the flexible circuit board, wherein each element of the array includes two transducer coils in a paired arrangement. A receive circuit connected to the coils is tuned to a resonant frequency, and the transducer coils operate in a send/receive mode. In another feature of the invention, there are means for converting a change in measured resonance to a visual display of the depth and width of the surface defect.

Abstract: The system and method provides a means for inspecting pipelines that have obstructions which prevent conventional inspection pigs from passing the obstructions. The invention uses remote-field eddy current inspection techniques and a uniquely configured excitation coil for inline inspection of pipelines having valves and other fittings that severely restrict or prevent the use of conventional inspection pigs. A unique collapsible excitation coil and a collapsible sensor array enables an inspection pig using these features to pass pipeline obstructions that prevent passage by conventional inspection pigs. The collapsible coil and sensor array provide means for reducing the diameter of an inspection pig to enable it to pass obstructions in the pipeline.

Abstract: A method and system for performing in-line measurement of stresses in pipeline walls by continuous Barkhausen method comprises an inspection pig including permanent or DC electromagnets for generating a magnetic field that moves with the inspection pig through a pipeline, inductive or other types of magnetic field sensors for reading Barkhausen noise signals generated by the moving magnetic field, and associated instrumentation for amplifying, filtering, detecting and storing the Barkhausen noise signals. The size of the sensors may be selected to match the size of defects being investigated. By comparing trending data over time to determine changes in Barkhausen noise levels, greater detection sensitivity may be achieved. The method may be particularly advantageous for use in inspection pigs that also use magnetic flux leakage to determine pipeline defects, since the magnetic flux leakage method also use permanent or DC electromagnets.

Abstract: The system and method provides a means for inspecting pipelines that have obstructions which prevent conventional inspection pigs from passing the obstructions. The invention is a system and method that uses remote-field eddy current inspection techniques and a uniquely configured excitation coil for inline inspection of pipelines having valves and other fittings that severely restrict or prevent the use of conventional inspection pigs. The invention relies on a unique collapsible excitation coil and a collapsible sensor array that enables an inspection pig incorporating the invention to pass pipeline obstructions that prevent passage by conventional inspection pigs. The invention provides a means for reducing the diameter of the inspection pig to enable it to pass obstructions in the pipeline.

Abstract: A method and system for performing in-line measurement of stresses in pipeline walls by continuous Barkhausen method comprises an inspection pig including permanent or DC electromagnets for generating a magnetic field that moves with the inspection pig through a pipeline, inductive or other types of magnetic field sensors for reading Barkhausen noise signals generated by the moving magnetic field, and associated instrumentation for amplifying, filtering, detecting and storing the Barkhausen noise signals. The size of the sensors may be selected to match the size of defects being investigated. By comparing trending data over time to determine changes in Barkhausen noise levels, greater detection sensitivity may be achieved. The method may be particularly advantageous for use in inspection pigs that also use magnetic flux leakage to determine pipeline defects, since the magnetic flux leakage method also use permanent or DC electromagnets.

Abstract: A method and apparatus is shown for implementing magnetostrictive sensor techniques for the nondestructive evaluation of ferromagnetic pipes or tubes. A magnetostrictive sensor generates shear waves and/or torsional waves in ferromagnetic pipes or tubes, which waves travel therethrough in a direction parallel to the longitudinal axis of the pipe. A circumferential magnetization is generated in the ferromagnetic pipe or tube by a DC or low frequency voltage establishing a current along the longitudinal axis and past the magnetostrictive sensor. Reflected shear or torsional waves may represent defects in the pipe or tube.

Abstract: A nondestructive method for inspecting steel pipelines for plastically deformed regions caused by mechanical damage to the pipeline. The invention is a method and system that uses nonlinear harmonic detection methods to detect mechanical damage in pipelines. The invention uses a time-varying magnetic field to sense magnetic properties of the pipeline. The odd-numbered harmonic frequencies are detected and their amplitudes are related to the magnetic condition of the material under test to determine areas of mechanical damage. This technique can be used for rapidly surveying stress states in pipelines where nonlinear harmonic sensing devices are attached to a pigging device moving through a pipeline at a relatively high rate of speed.