Abstract
Pulsed eddy current testing of wall-thinning through cladding and insulation was studied from both theoretical and experimental aspects. The analytical solution was derived for a simplified four-layered structure and was used to conduct simulations to ascertain the feasibility of this method. A pulsed eddy current testing probe consisting of a circular excitation coil and an AMR-sensor-embedded differential detector was fabricated to measure the time-varying magnetic field signals on the axisymmetric excitation coil's axis. The measurement system was able to measure magnetic field down to a few hundred micro-Gausses in an unshielded environment. Simulation and test results showed that over a certain time after turning off the excitation current the magnetic field signal's decay behavior is almost merely relevant to the pipe's wall thickness. Future development of a carbon steel pipe's wall-thinning can be evaluated by using decay coefficients estimated from previously obtained test data.
Original language | English |
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Pages (from-to) | 215-224 |
Number of pages | 10 |
Journal | Journal of Nondestructive Evaluation |
Volume | 31 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2012 Sep |
Externally published | Yes |
Keywords
- AMR sensor
- Analytical solution
- Magnetic field measurement
- Pulsed eddy current testing
- Wall-thinning
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering