Procedure and device for detecting nonuniformities in the wall thickness of inaccessible metal pipes
First Claim
1. Test procedure for detecting nonuniformities in the wall thickness of inaccessible metallic pipes, characterized in that electrical alternating currents having at least two different frequency components having approximately the same amplitude are simultaneously passed through the pipe, a return current being passed through a return line, and the magnetic fields generated by the alternating currents are measured at a certain measuring distance outside the pipe.
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0 Petitions
Accused Products
Abstract
The invention concerns a testing procedure for detecting nonuniformities in the wall thickness of inaccessible metallic pipes in which electrical alternating currents of different frequencies are passed through the pipe and the magnetic fields generated by them are measured outside the pipe. The invention further concerns a device, particularly for carrying out the testing procedure, comprising a power source for passing an alternating current through the pipe, at least one magnetic field probe for measuring outside the pipe the magnetic field generated by the alternating current, and equipment for the evaluation which deduces the presence of a nonuniformity in wall thickness from the magnetic field signal of the magnetic field probe.
13 Citations
15 Claims
- 1. Test procedure for detecting nonuniformities in the wall thickness of inaccessible metallic pipes, characterized in that electrical alternating currents having at least two different frequency components having approximately the same amplitude are simultaneously passed through the pipe, a return current being passed through a return line, and the magnetic fields generated by the alternating currents are measured at a certain measuring distance outside the pipe.
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12. Device, for detecting nonuniformities in the wall thickness of inaccessible pipes comprising;
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a power source (5) to simultaneously pass alternating currents of different frequencies through the pipe (6), at least one magnetic field probe (10) arranged at a measuring distance from the pipe (6) to measure outside the pipe (6) the magnetic fields generated by the alternating currents, and equipment for evaluation (9) to deduce the presence of a nonuniformity it wall thickness from the magnetic field signal of the magnetic field probe (10). - View Dependent Claims (13, 14)
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Specification