Detection and Characterisation of Conductive Objects Using Electromagnetic Induction and a Fluxgate Magnetometer

Elson, Lucy; Meraki, Adil; Rushton, Lucas M.; Pyragius, Tadas; Jensen, Kasper

Abstract

Eddy currents induced in electrically conductive objects can be used to locate metallic objects as well as to assess the properties of materials non-destructively without physical contact. This technique is useful for material identification, such as measuring conductivity and for discriminating whether a sample is magnetic or non-magnetic. In this study, we carried out experiments and numerical simulations for the evaluation of conductive objects. We investigated the frequency dependence of the secondary magnetic field generated by induced eddy currents when a conductive object is placed in a primary oscillating magnetic field. According to electromagnetic theory, conductive objects have different responses at different frequencies. Using a table-top setup consisting of a fluxgate magnetometer and a primary coil generating a magnetic field with frequency up to 1 kHz, we were able to detect aluminium and steel cylinders using the principle of electromagnetic induction. The experimental results were compared to numerical simulations, with good overall agreement. This technique enables the identification and characterisation of objects using their electrical conductivity and magnetic permeability.

Citation

Elson, L., Meraki, A., Rushton, L. M., Pyragius, T., & Jensen, K. (2022). Detection and Characterisation of Conductive Objects Using Electromagnetic Induction and a Fluxgate Magnetometer. Sensors, 22(16), Article 5934. https://doi.org/10.3390/s22165934

• Journal Article Type: Article
• Acceptance Date: Aug 6, 2022
• Online Publication Date: Aug 9, 2022
• Publication Date: Aug 1, 2022
• Deposit Date: Aug 13, 2022
• Publicly Available Date: Aug 15, 2022
• Journal: Sensors
• Publisher: MDPI AG
• Peer Reviewed: Peer Reviewed
• Volume: 22
• Issue: 16
• Article Number: 5934
• DOI: https://doi.org/10.3390/s22165934
• Keywords: electromagnetic induction, conductivity, eddy current, magnetic field, non-destructive testing, numerical simulation, magnetic permeability, fluxgate magnetometer
• Public URL: https://nottingham-repository.worktribe.com/output/9906926
• Publisher URL: https://www.mdpi.com/1424-8220/22/16/5934