Abstract

Eddy current testing (ECT) at different frequencies can identify surface and back-surface defects caused by the skin effect. Traditional ECT uses a pickup coil to measure the magnetic-field signal caused by eddy current. However, according to Faraday’s law of electromagnetic induction, the voltage signal detected at low frequencies is weak; thus, the signal is susceptible to interference from noise. By contrast, magnetoresistive (MR) sensors have high sensitivity at low frequencies. Therefore, we developed a rectangular wave eddy current testing system using an MR sensor. The system uses rectangular wave excitation, which can generate both low- and high-frequency signals, and the MR sensor detects the magnetic-field components. A 12-mm-thick aluminum plate with an artificial circular defect 10 mm in diameter and 4 mm in height was used as a specimen. The measurement results indicated that the developed system can accurately and quickly distinguish between surface and back-surface defects.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.