Quantifying the Relative Thickness of Conductive Ferromagnetic Materials Using Detector Coil-Based Pulsed Eddy...

Area of Science:

• Materials Science
• Electrical Engineering
• Non-Destructive Evaluation (NDE)

Background:

• Non-destructive evaluation (NDE) is vital for monitoring the structural health of infrastructure, particularly large conductive ferromagnetic pipes.
• Pulsed eddy current (PEC) sensing, especially with detector coil-based architectures, is an effective NDE technique for thickness quantification.
• Previous research highlights the utility of PEC signal decay rates for thickness measurement, showing robustness against sensor variations.

Purpose of the Study:

• To present a novel protocol for conductive ferromagnetic material thickness quantification using PEC sensor detector coil voltage decay rates.
• To address the calibration challenges associated with in situ applications of PEC-based thickness assessment.
• To enable relative thickness quantification without the need for material property measurements or calibration samples.

Main Methods:

• Utilizing the decay rate of the detector coil-based time-domain PEC signal.
• Developing a protocol for relative thickness quantification based on the established decay rate method.
• Focusing on applications for large diameter conductive ferromagnetic pipes, such as those in the energy and water sectors.

Main Results:

• Demonstrated a method for thickness quantification that is independent of sensor specifics (shape, size, coil turns) and excitation current.
• Successfully quantified relative thickness without requiring calibration, overcoming practical limitations of in situ assessments.
• Showcased the effectiveness of the decay rate-based method, previously shown for grey cast iron pipes.

Conclusions:

• The proposed protocol offers a calibration-free approach for relative thickness quantification of conductive ferromagnetic materials using PEC.
• This method enhances the practicality of structural health monitoring for critical infrastructure like pipes, especially in challenging field conditions.
• The findings contribute to advancing NDE techniques for reliable and accessible material assessment.