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New eddy current probe for thickness gauging of conductive materials
N DT Abstracts pursue this possibility further from the analysis point of view. We will fu~t describe an actual implementation of this approach, and then present experimental data that verify the method.
56300 Thollon, F.; Burais, N. Automatic optimisation of sensor for non-destructive control and evaluation by Eddy currents (In French, English abstract) Revue Pratique de Controle Industriel, No. 188, pp. 31-36 (Sep. 1994) Design of N.D.T. and N.D.E., sensors is possible by solving Maxwell's relations with FEM or BIM. But the great number of geometrical and electrical parameters of sensor and tested material implies many results that don't give necessarily a well adapted sensor. The authors have used a genetic algorithm for automatic optimization. After having tested this algorithm with analytical solution of Maxwell's relations for cladding thickness measurement, the method has been implemented in Finite Element package and applied to the design of sensor for cracks detection under installed fasteners in aircraft structure.
56966 Harfieid, N.; Bowler, J.R. Analytical calculations of eddy current probe impedance response to cracks Review of Progress in Quantitative Nondostruction Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. VoL 13A, pp. 279- 286. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 The Wieuer-Hopf technique was developed in about 1931 in order to solve a particular class of integral equation, in 1952 D. S. Jones published an approach in which transforms are applied directly to the partial differential equation and the complex variable equation found without the formulation of an integral equation. Jones's method is used in obtaining the solution for the magnetic field.
56090 Savin, A.; Griraberg, R.; Andreescu, A.; Chifan, S.; Plavanescu, R.; Mihalache, 0. Eddy current transducers for special applications. (In Romanian, English abstract)
56786 Phillips, L.C. Eddy current liquid metal flow rate sensor
Simpozionul Asociatiei Romane do Examinari Nedistructive, Huncdoara (Romania), 11-13 May 1994. Vol. l-A, pp. 207-214. ARoENd (1994) The present work is meant to be a presentation of the theory of the eddy current transducers working for special applications --rotating magnetic field transducers and rectangular coils transducers. This theory was drawn up in purpose to find some calculations to permit designing and optimizing of the transducers working. Theoretical data were compared with the experimental ones and we found they were in a perfect concordance. This method allows a 3D data presentation for the material jogs, practicing a numerical processing of the informations assisted by an electronic computer.
Review of Progress in Quantitative Nondostruction Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. VoL 13B, pp. 2265- 2271. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 The objective of this project has been to establish the feasibility of using an eddy current sensor in measuring the liquid metal flow rate during the production of metal powders. This project explores the application of a non-contact eddy current sensor by modeling the phenomenon, and conducting a series of room temperature experimentswith liquid mercury for verification.
Fastritskii, V.C.; Vingris, L.T. Increasing the thermal stability of superposed parametric 55779
Wincheski, B.; Fulton, J.; Nath, S.; Namkung, M. New eddy current probe for thickness gauging of conductive 56783
eddy-current transducers Russian Journal of Nondestructive Testing, Vol. 29, No. 9, pp. 650-651 (May 1994) Studies have been carried out on variation of the temperature dependencies of superposed eddy-current transducers. Practical recommendations are given for increasing the thermal stability of superposed parametric eddy-current transducers.
materials Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. Vol. 13B, pp. 1939- 1946. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 This new eddy current probe has been used to accurately measure the thickness of aluminum alloy plates with a resolution of greater than 0.001" (25 I~m).Simulated corrosion damage has also been detected on both single layer and multi-layer samples. The present work will explain the output voltage dependence of the device as a function of material thickness and present experimental results for thickness gauging and corrosion detection.
55607 Placko, D.; Dufour, I. A focused.field eddy current sensor for nondestructive testing IEEE Transactions on Magnetics, Vol. 29, No. 6, pp. 3192-3194 (Nov. 1993) We present an original structure of eddy current sensor meant for nondestructive testing of electrically conducting materials. We propose an idea, which consists of exploiting the good directivity of large cup sensors associated to a particular set of measurements, in order to extract relevant information only about the small part of the eddy currents induced in the target, below the centre of the sensor. The interest of this method is illustrated by scanning graphite composite plates containing small defects with this novel sensor. The comparison of the results obtained with actual sensors and our focused- field sensor demonstrates the efficiency of the structure.
Namkung, M.; Fulton, J.P.; Wincheski, B.; Clendenin, C.G. An application of a new electromagnetic sensor to real-time monitoring of fatigue crack growth in thin metal plates
56781
Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. Vol. 13B, pp. 1633- 1640. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 The present work is an initial study on applying eddy current-type probes to monitoring fatiqne crack growth. The performance of two types of electromagnetic probes, a conventional eddy current probe and a newly developed self-nulling probe, was evaluated for the detection characteristics at and near the tips of fatigue cracks. The scan results show that the latter probe provides a very well defined local maximum in its output in the crack tip region suggesting the definite possibility of precisely locating the tip, while the former provides a somewhat ambiguous distribution of the sensor output in the same region.
55342 Shyamsunder, M.T.; Rao, B.P.C.; Babu Rao, C.; Bhattacharya, D.K.; Raj, B. A new tandem probe design for phased.array eddy current testing Insight, Vol. 36, No. 6, pp. 434-436 (Jun. 1994) A relatively new eddy current technique is Phased-Array Eddy Current Testing (PAECT). We briefly discuss the principles of PAECI'. One of the limitations of PAECT, the low sensitivity zone of PAEC probes and its consequence, is discussed in detail. A modified probe design to overcome this low sensitivity area of PAEC probes is presented.
56507 Khandetskii, V,S. Influence of a separation of a weakly conducting composite material on the parameters of an eddy current transducer with a plane-parallel field
54977 Kamimura,A.; Aoki, K.; Komatsu, H.; Matsumoto, Y.; Shigemitsu, T.; Kishi, Y.; Hashimoto, M.; Miya, K. Study of the magnetic flux control eddy c u r r e n t probe for steam generator tube inspection
Russian Journal of Nondestructive Testing, Vol. 29, No. 12, pp. 896- 902 (Dec. 1993) A separation is represented in the form of an infinite thin nonconducting sheet located parallel to the outer boundary in the depth of the material. The influence of eddy currents formed in the layer adjoiningthe boundary of the separation on the parameters of the eddy current transducer in the form of a strip of parallel current lines lying on the outer surface is investigated. Approximate analytical expressions are obtained for the resistances introduced into the eddy current transducer. The results of theoretical calculations are compared with experimental data.
11 th International Conference and Exhibits on NDE in the Nuclear and Pressure Vessel Industries, Albuquerque, New Mexico (United States), 30 Apr. - 2 May 1992. pp. 63-69. ASM International (1992). ISBN 0-87170- 446-3 An innovative ECT probe called "Magnetic-Flux-Control (MAC) probe" was designed for the future application to the in-service inspection of SG tubings at each outage in order to improve the detection capability of the
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56300 Thollon, F.; Burais, N. Automatic optimisation of sensor for non-destructive control and evaluation by Eddy currents (In French, English abstract) Revue Pratique de Controle Industriel, No. 188, pp. 31-36 (Sep. 1994) Design of N.D.T. and N.D.E., sensors is possible by solving Maxwell's relations with FEM or BIM. But the great number of geometrical and electrical parameters of sensor and tested material implies many results that don't give necessarily a well adapted sensor. The authors have used a genetic algorithm for automatic optimization. After having tested this algorithm with analytical solution of Maxwell's relations for cladding thickness measurement, the method has been implemented in Finite Element package and applied to the design of sensor for cracks detection under installed fasteners in aircraft structure.
56966 Harfieid, N.; Bowler, J.R. Analytical calculations of eddy current probe impedance response to cracks Review of Progress in Quantitative Nondostruction Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. VoL 13A, pp. 279- 286. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 The Wieuer-Hopf technique was developed in about 1931 in order to solve a particular class of integral equation, in 1952 D. S. Jones published an approach in which transforms are applied directly to the partial differential equation and the complex variable equation found without the formulation of an integral equation. Jones's method is used in obtaining the solution for the magnetic field.
56090 Savin, A.; Griraberg, R.; Andreescu, A.; Chifan, S.; Plavanescu, R.; Mihalache, 0. Eddy current transducers for special applications. (In Romanian, English abstract)
56786 Phillips, L.C. Eddy current liquid metal flow rate sensor
Simpozionul Asociatiei Romane do Examinari Nedistructive, Huncdoara (Romania), 11-13 May 1994. Vol. l-A, pp. 207-214. ARoENd (1994) The present work is meant to be a presentation of the theory of the eddy current transducers working for special applications --rotating magnetic field transducers and rectangular coils transducers. This theory was drawn up in purpose to find some calculations to permit designing and optimizing of the transducers working. Theoretical data were compared with the experimental ones and we found they were in a perfect concordance. This method allows a 3D data presentation for the material jogs, practicing a numerical processing of the informations assisted by an electronic computer.
Review of Progress in Quantitative Nondostruction Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. VoL 13B, pp. 2265- 2271. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 The objective of this project has been to establish the feasibility of using an eddy current sensor in measuring the liquid metal flow rate during the production of metal powders. This project explores the application of a non-contact eddy current sensor by modeling the phenomenon, and conducting a series of room temperature experimentswith liquid mercury for verification.
Fastritskii, V.C.; Vingris, L.T. Increasing the thermal stability of superposed parametric 55779
Wincheski, B.; Fulton, J.; Nath, S.; Namkung, M. New eddy current probe for thickness gauging of conductive 56783
eddy-current transducers Russian Journal of Nondestructive Testing, Vol. 29, No. 9, pp. 650-651 (May 1994) Studies have been carried out on variation of the temperature dependencies of superposed eddy-current transducers. Practical recommendations are given for increasing the thermal stability of superposed parametric eddy-current transducers.
materials Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. Vol. 13B, pp. 1939- 1946. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 This new eddy current probe has been used to accurately measure the thickness of aluminum alloy plates with a resolution of greater than 0.001" (25 I~m).Simulated corrosion damage has also been detected on both single layer and multi-layer samples. The present work will explain the output voltage dependence of the device as a function of material thickness and present experimental results for thickness gauging and corrosion detection.
55607 Placko, D.; Dufour, I. A focused.field eddy current sensor for nondestructive testing IEEE Transactions on Magnetics, Vol. 29, No. 6, pp. 3192-3194 (Nov. 1993) We present an original structure of eddy current sensor meant for nondestructive testing of electrically conducting materials. We propose an idea, which consists of exploiting the good directivity of large cup sensors associated to a particular set of measurements, in order to extract relevant information only about the small part of the eddy currents induced in the target, below the centre of the sensor. The interest of this method is illustrated by scanning graphite composite plates containing small defects with this novel sensor. The comparison of the results obtained with actual sensors and our focused- field sensor demonstrates the efficiency of the structure.
Namkung, M.; Fulton, J.P.; Wincheski, B.; Clendenin, C.G. An application of a new electromagnetic sensor to real-time monitoring of fatigue crack growth in thin metal plates
56781
Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. Vol. 13B, pp. 1633- 1640. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 The present work is an initial study on applying eddy current-type probes to monitoring fatiqne crack growth. The performance of two types of electromagnetic probes, a conventional eddy current probe and a newly developed self-nulling probe, was evaluated for the detection characteristics at and near the tips of fatigue cracks. The scan results show that the latter probe provides a very well defined local maximum in its output in the crack tip region suggesting the definite possibility of precisely locating the tip, while the former provides a somewhat ambiguous distribution of the sensor output in the same region.
55342 Shyamsunder, M.T.; Rao, B.P.C.; Babu Rao, C.; Bhattacharya, D.K.; Raj, B. A new tandem probe design for phased.array eddy current testing Insight, Vol. 36, No. 6, pp. 434-436 (Jun. 1994) A relatively new eddy current technique is Phased-Array Eddy Current Testing (PAECT). We briefly discuss the principles of PAECI'. One of the limitations of PAECT, the low sensitivity zone of PAEC probes and its consequence, is discussed in detail. A modified probe design to overcome this low sensitivity area of PAEC probes is presented.
56507 Khandetskii, V,S. Influence of a separation of a weakly conducting composite material on the parameters of an eddy current transducer with a plane-parallel field
54977 Kamimura,A.; Aoki, K.; Komatsu, H.; Matsumoto, Y.; Shigemitsu, T.; Kishi, Y.; Hashimoto, M.; Miya, K. Study of the magnetic flux control eddy c u r r e n t probe for steam generator tube inspection
Russian Journal of Nondestructive Testing, Vol. 29, No. 12, pp. 896- 902 (Dec. 1993) A separation is represented in the form of an infinite thin nonconducting sheet located parallel to the outer boundary in the depth of the material. The influence of eddy currents formed in the layer adjoiningthe boundary of the separation on the parameters of the eddy current transducer in the form of a strip of parallel current lines lying on the outer surface is investigated. Approximate analytical expressions are obtained for the resistances introduced into the eddy current transducer. The results of theoretical calculations are compared with experimental data.
11 th International Conference and Exhibits on NDE in the Nuclear and Pressure Vessel Industries, Albuquerque, New Mexico (United States), 30 Apr. - 2 May 1992. pp. 63-69. ASM International (1992). ISBN 0-87170- 446-3 An innovative ECT probe called "Magnetic-Flux-Control (MAC) probe" was designed for the future application to the in-service inspection of SG tubings at each outage in order to improve the detection capability of the
246