{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:18:15Z","timestamp":1760149095593,"version":"build-2065373602"},"reference-count":20,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2023,7,1]],"date-time":"2023-07-01T00:00:00Z","timestamp":1688169600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Slovak Research and Development Agency","award":["APVV-19-0214"],"award-info":[{"award-number":["APVV-19-0214"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The article discusses the practical application of the method of electromagnetic non-destructive investigation of austenitic materials. To identify and evaluate deep artificial defects, the sweep-frequency eddy current method with harmonic excitation is used. The objects of interest are the surface electric-discharged machined notches, with a defined geometry, fabricated in a plate with a thickness of 30 mm. An innovative eddy current probe with a separate excitation and detection circuit is used for the investigation. The achieved results clearly demonstrate the robustness and potential of the method, especially for deep defects in thick material. By using the fifth probe in connection with the frequency sweeping of eddy currents, it is possible to reliably detect artificial defects up to 24 \u00b1 0.5 mm deep by using low-frequency excitation signals. An important fact is that the measuring probe does not have to be placed directly above the examined defect. The experimental results achieved are presented and discussed in this paper. The conducted study can serve, for example, as an input database of defect signals with a defined geometry to increase the convergence of learning networks and for the prediction of the geometry of real (fatigue and stress-corrosion) defects.<\/jats:p>","DOI":"10.3390\/s23136085","type":"journal-article","created":{"date-parts":[[2023,7,3]],"date-time":"2023-07-03T00:53:16Z","timestamp":1688345596000},"page":"6085","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Progress in Evaluation of Deep Artificial Defects from Sweep-Frequency Eddy-Current Testing Signals"],"prefix":"10.3390","volume":"23","author":[{"given":"Milan","family":"Smetana","sequence":"first","affiliation":[{"name":"Department of Electromagnetic and Biomedical Engineering, Faculty of Electrical Engineering and Information Technology, University of Zilina, Univerzitna 8215\/1, 010 26 Zilina, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4855-0303","authenticated-orcid":false,"given":"Daniela","family":"Gombarska","sequence":"additional","affiliation":[{"name":"Department of Electromagnetic and Biomedical Engineering, Faculty of Electrical Engineering and Information Technology, University of Zilina, Univerzitna 8215\/1, 010 26 Zilina, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zuzana","family":"Psenakova","sequence":"additional","affiliation":[{"name":"Department of Electromagnetic and Biomedical Engineering, Faculty of Electrical Engineering and Information Technology, University of Zilina, Univerzitna 8215\/1, 010 26 Zilina, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Chady, T., and Grochowalski, J.M. (2019). Eddy Current Transducer with Rotating Permanent Magnets to Test Planar Conducting Plates. Sensors, 19.","DOI":"10.3390\/s19061408"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"110249","DOI":"10.1016\/j.measurement.2021.110249","article-title":"Swept-Frequency eddy current excitation for TMR array sensor and Pulse-Compression: Feasibility study and quantitative comparison of time and frequency domains processing","volume":"187","author":"Ye","year":"2022","journal-title":"Measurement"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.ndteint.2014.04.009","article-title":"Near electrical resonance signal enhancement (NERSE) in eddy-current crack detection","volume":"66","author":"Hughes","year":"2014","journal-title":"NDT E Int."},{"key":"ref_4","unstructured":"Goda, T., Haga, Y., Tomioka, T., Sakai, K., Kiwa, T., and Tsukada, K. (2018). Electromagnetic Non-Destructive Evaluation (XXI), IOS Press."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4558","DOI":"10.1109\/JSEN.2017.2710356","article-title":"Thickness Measurement of Metal Plates Using Swept-Frequency Eddy Current Testing and Impedance Normalization","volume":"17","author":"Cheng","year":"2017","journal-title":"IEEE Sens. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2525","DOI":"10.3390\/s110302525","article-title":"Non-Destructive Techniques Based on Eddy Current Testing","volume":"11","year":"2011","journal-title":"Sensors"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"102308","DOI":"10.1016\/j.ndteint.2020.102308","article-title":"A novel approach for metallic coating detection through analogizing between coil impedance and plane wave impedance","volume":"116","author":"Xu","year":"2020","journal-title":"NDT E Int."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.3233\/JAE-2010-1232","article-title":"Enhancing information level in eddy-current non-destructive inspection","volume":"33","author":"Janousek","year":"2010","journal-title":"Int. J. Appl. Electromagn. Mech."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1079","DOI":"10.1109\/TMAG.2006.870967","article-title":"Shape reconstruction of multiple cracks from ECT signals by means of a stochastic method","volume":"42","author":"Rebican","year":"2006","journal-title":"IEEE Trans. Magn."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"035009","DOI":"10.1063\/1.5079959","article-title":"Characterization of multilayered structures by swept-frequency eddy current testing","volume":"9","author":"Cheng","year":"2019","journal-title":"AIP Adv."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.ndteint.2012.12.002","article-title":"Rotating field eddy current probe with bobbin pickup coil for steam generator tubes inspection","volume":"54","author":"Xin","year":"2013","journal-title":"NDT E Int."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2102","DOI":"10.1016\/j.matlet.2004.01.006","article-title":"Remote field eddy current testing for detection of stress corrosion cracks in gas transmission pipelines","volume":"58","author":"Kim","year":"2004","journal-title":"Mater. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Smetana, M., Gombarska, D., and Janousek LVaverka, F. (2022). Multi-Point Interaction of Partially Conductive Cracks with Sweep Frequency Eddy Currents in Electromagnetic Non-Destructive Evaluation. Appl. Sci., 12.","DOI":"10.3390\/app122211451"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Santos, D., Machado, M.A., Jose, J.M., Carla, P.S., Proen\u00e7a, S., Crivellaro, F.S., Rosado, L.S., and Santos, T.G. (2023). Non-Destructive Inspection of High Temperature Piping Combining Ultrasound and Eddy Current Testing. Sensors, 23.","DOI":"10.3390\/s23063348"},{"key":"ref_15","first-page":"230","article-title":"Non-destructive Testing by Inovated Approach Using Swept Frequency with Various Eddy Current Probes","volume":"41","author":"Stubendekova","year":"2016","journal-title":"Stud. Appl. Electromagn. Mech."},{"key":"ref_16","unstructured":"Smetana, M., Capova, K., Chudacik, V., Palcek, P., and Oravcova, M. (2021). Influence of the Heat Treatment on Magnetic Properties of Austenitic Steels, IOS Press. Studies in Applied Electromagnetics and Mechanics E-book Volume 42: Electromagnetic Nondestructive Evaluation (XX)."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Dziczkowski, L., and Tytko, G. (2023). Evaluation of the Properties of Eddy Current Sensors Based on Their Equivalent Parameters. Sensors, 23.","DOI":"10.3390\/s23063267"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1080\/10589750802195469","article-title":"Development of computational inversion techniques to size cracks from eddy current signals","volume":"24","author":"Yusa","year":"2009","journal-title":"Nondestruct. Test. Eval."},{"key":"ref_19","unstructured":"Ribeiro, L.A., Pasadas, D., Ramos, H.G., and Rocha, T. (2015, January 21\u201323). Regularization of the inversion process in eddy current characterization of superficial defects. Proceedings of the 20th International Workshop on Electromagnetic Non-destructive Evaluation, Sendai, Japan."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"204","DOI":"10.5545\/sv-jme.2010.171","article-title":"Electromagnetic non-destructive evaluation: Present and future","volume":"57","author":"Grimberg","year":"2011","journal-title":"J. Mech. Eng."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/13\/6085\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:04:41Z","timestamp":1760126681000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/13\/6085"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,7,1]]},"references-count":20,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2023,7]]}},"alternative-id":["s23136085"],"URL":"https:\/\/doi.org\/10.3390\/s23136085","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2023,7,1]]}}}