Abstract
For detection of sub-surface defects using eddy current (EC) method, increasing the depth of penetration of ECs is essential. This can be achieved through strengthening of the primary magnetic field from the EC probe. This can be accomplished by using low-frequency high amplitude excitation current, precise phase lag measurement and high throughput probes. Working on these lines, the paper presents development of lock-in amplifier based EC instrument and cup-core send-receive type probe. Experiment results indicate that the proposed instrument and probe is able to detect sub-surface defects located at 8.0 mm below surface and classify sub-surface as well as surface defects in stainless steel plate.
Similar content being viewed by others
References
Libby, H. L. (1971). Introduction to electromagnetic non-destructive test methods. Hoboken: Wiley.
Javier, G. M., Jaime, G.-G., & Ernesto, V.-S. (2011). Non-destructive techniques based on Eddy current testing. Sensors, 11, 2525–2565.
Atzlesberger, J., Zagar, B. G., Cihal, R., Brummayer, M., & Reisinger, P. (2013). Sub-surface defect detection in a steel sheet. Measurement Science and Technology, 24, 084003.
Joubert, P. Y., Vourc’h, E., Tassin, A., & Diraison, Y. L. (2010). Source separation techniques applied to the detection of subsurface defects in the eddy current NDT of aeronautical lap-joints. NDT&E International, 43, 606–614.
Rao, B. P. C. (2007). Practical Eddy current testing (pp. 49–53). New Delhi: Narosa Publishing House Pvt. Ltd.
Dario, P., Rocha, T. J., Ramos, H. G., & Ribeiro, A. L. (2012). Evaluation of portable ECT instruments with positioning capability. Measurement, 45, 393–404.
Yating, Y., Yang, T., & Pingan, D. (2012). A new Eddy current displacement measuring instrument independent of sample electromagnetic properties. NDT&E International, 48, 16–22.
Chady, T., Psuj, G., Sikora, R., Kowalczyk, J., & Spychalski, I. (2014). Eddy current system for inspection of train hollow axles. AIP Conference Proceedings, 1581(1), 1387–1392.
Palanisamy, P., & Lakin, K. M. (1983). Development of EC inspection technique for sleeved engine disk, bolt holes. Review of Progress in Quantitative Non-destructive Evaluation, 2A, 205–223.
Vernon, S. N., & Gross, T. A. O. (1987). Effect of shielding on properties of eddy current probe with ferrite cup-core. Review of Progress in Quantitative Non-destructive Evaluation, 6A, 713–719.
Vourc’h, E., Joubert, P. Y., Le Gac, G., & Larzabal, P. (2013). Non-destructive evaluation of loose assemblies using multi-frequency Eddy currents and artificial neural networks. Measurement Science and Technology, 24, 125604.
Udpa, S. S., & Moore, P. O. (2004). Non-destructive testing handbook third edition volume 5 electromagnetic testing (pp. 132–151). Ohio: American Society of Nondestructive Testing.
Ribeiro, A. L. & Ramos, H. G. (2008). Inductive probe for flaw detection in non-magnetic metallic plates using Eddy currents. In Proceedings of I2MTC-IEEE international instrumentation and measurement technology conference, Victoria, Canada (pp. 1447–1453).
Park, D. G., Angani, C. S., Kim, G. D., Kim, C. G., & Cheong, Y. M. (2009). Evaluation of pulsed Eddy current response and detection of the thickness variation in the stainless steel. IEEE Transactions on Magnetics, 45(10), 3893–3896.
Nair, N. V., Melapudi, V. R., Jimenez, H. R., Liu, X., Deng, Y., Zeng, Z., et al. (2006). A GMR-based Eddy current system for NDE of aircraft structures. IEEE Transactions on Magnetics, 42(10), 3312–3314.
Clarkson, P., Esward, T. J., Harris, P. M., Smith, A. A., & Smith, I. M. (2010). Software simulation of a lock-in amplifier with application to the evaluation of uncertainties in real measuring systems. Measurement Science and Technology, 21, 045106.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Soni, A.K., Rao, B.P. Lock-in Amplifier Based Eddy Current Instrument for Detection of Sub-surface Defect in Stainless Steel Plates. Sens Imaging 19, 32 (2018). https://doi.org/10.1007/s11220-018-0217-8
Received:
Revised:
Published:
DOI: https://doi.org/10.1007/s11220-018-0217-8