Selection of the frequency of eddy currents in non-destructive testing of non-ferromagnetic plates

• Autorzy: Dziczkowski L.
• Języki publikacji: EN

Abstrakty

EN

Purpose: To determine the optimal frequency of the electromagnetic field exciting eddy currents during the search for surface defects in non-ferromagnetic materials or at the time of conductivity measurements by means of eddy currents methods. Design/methodology/approach: On the grounds of a mathematical model of a contact coil located above a conductive non-ferromagnetic plate, the sensitivities to the measured parameters were designated. Furthermore, a new definition of eddy currents penetration depth was proposed. Findings: Recommendations facilitating proper selection of the electromagnetic field frequency were formulated, depending on specific applications. Practical implications: The discussed phenomena and calculations are useful not only to constructors of the devices utilising the phenomenon of eddy currents, but also to users of flaw detectors and conductometers. Originality/value: A modified definition of the actual penetration depth of eddy currents is proposed in the paper, which differs from the classical approach based on the 1/e level. The new definition may be very convenient and useful for operators utilising eddy current devices. The described sensitivity model facilitates setting up the devices for a specific task involved in a given process technology.

Słowa kluczowe

EN

non-destructive testing; eddy currents; flaw detection; conductometry

PL

badania nieniszczące; prądy wirowe; defektoskopia; konduktometria

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2008
• Tom: Vol. 27, nr 1
• Strony: 43--46
• Opis fizyczny: Bibliogr. 15 poz., wykr.

Twórcy

autor

Dziczkowski L.

• Silesian University of Technology, ul. Akademicka 16, 44-100 Gliwice, Poland,

Bibliografia

• [1] R. Sikora, K. M. Gawrylczuk, M. Gramaz, S. Gratkowski, Computer models of eddy-current probes in flaw detection and conductivity testing eqipment, Scientific book of The Silesian University of Technology, Eddy currents in non-destruction testing Z111 Gliwice, 1993, 51-79 (in Polish).
• [2] K. Nita, P. Tarnowski, S. F. Filipowicz, Z. Giza, J. Sikora, Resistance scanner, Proceedings of the 24th International Conference on Fundamental of Electrotechnics and Circuit Theory, XXIVIC-SPETO'01, Gliwice, 2001, 523-527.
• [3] A. Lewinska-Romicka, Non-destructive testing. WNT Warszawa 2001 (in Polish).
• [4] L. Dziczkowski, M. Dziczkowska, A useful mathematical model for analysis of non-magnetic thin foil on the grounds of the eddy current method. Mašinostroenie i Technosfera XXI weka. Sprawnik Trudow XIV Meždunarodnoj Naučno-techničeskoj Konferencji, Donieck, 2007, 26-31.
• [5] L. Dziczkowski, The analysis of determining the conductance and thickness of thin non-magnetic foil by the eddy current method, Mašinostroenie i Technosfera XXI weka. Sprawnik Trudow XIV Meždunarodnoj Naučno-techničeskoj Konferencji, Donieck, 2007, 22-26.
• [6] L. Dziczkowski, Errors in the simultaneous determination of conductivity and foil thickness by the eddy curent method based on a single measurement, Avtomatizacja: Problemy, Idei, Rešenija, Materialy Meždunarodnoj Naučno-techničeskoj Konferencji, Sevastopol, 2007, 137-140.
• [7] M. Boujelbene, A. Moisan, W. Bouzid, S. Torbaty, Variation cutting speed the five axis milling, Journal of Achievements in Materials and Manufacturing Engineering 21/1 (2007) 7-14.
• [8] S. Malzacher, L. Dziczkowski, A comparative eddy current conductivity meter with analog reading, Scientific book of The Silesian University of Technology, Eddy currents in non-destruction testing Z111, Gliwice, 1993, 165-180 (in Polish).
• [9] R. Nowosielski, S. Griner, The shielding of magnetic fields by means of metallic glass laminar structures Fe78Si9B13,Proceedings of the 7th International Scientific Conference, “Achievements in Materials and Manufacturing Engineering”, AMME'98, Gliwice-Zakopane 1998, 381-386 (in Polish).
• [10] S. Griner, R. Nowosielski, The damping of magnetic fields by metallic glass shields Co60Ni10Fe5Si11B14, Proceedings of the 8thInternational Scientific Conference, “Achievements in Materials and Manufacturing Engineering”, AMME'99, Gliwice-Rydzyna-Pawłowice-Rokosowo, 1999, 229-232, (in Polish).
• [11] S. Griner, R. Nowosielski, The impact of the structural properties of electromagnetic fields shields mad of metallic glass Fe78Si9B13 on their dumping properties, Proceedings of the 8th International Scientific Conference, “Achievements in Materials and Manufacturing Engineering”, AMME'99, Gliwice-Rydzyna-Pawłowice-Rokosowo, 1999, 429-432, (in Polish).
• [12] B. Weiss, O. Biro, Multigrid for time-harmonic 3-D eddy current analysis with edge elements, IEEE Transactions on Magnetics 5 (2005) 1712-1715.
• [13] T. Theodoulidis, J. Bowler, Eddy-current interaction of long coil with a slot in a conductive plate, IEEE Transactions on Magnetics 4 (2005) 1238-1247.
• [14] K. Ishibashi, H. Fujita, Eddy Current Analysis of a Conductor With a Conductive Crack by Boundary Integral Equation Method, Proceedings of the 12th Biennial IEEE Conference on Electromagnetic Field Computation, Miami, 2006, 189-189.
• [15] G. Betta, L. Ferrigno, M. Laracca, Calibration and adjustment of an eddy current based multi-sensor probe for non-destructive testing, Proceedings of the Sensors for Industry Conference, 2nd ISA/IEEE, 2002, 120-124.