- Email: [email protected]
Eddy current probe for buried gas pipe inspection
Birks, A.S.; Ferris, R.H.; Doctor, P.G.; Clark, R.A.; Spanner, G.E. 37144
Reliability of eddy current examination of steam generator tubes l l t h World Conference on Nondestructive Testing, Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 162-168. Taylor Publishing Co., Dallas (1985). A unique study of nondestruct'i~,e examination reliability is underway at the Pacific Northwest Laboratory under U.S. Nuclear Regulatory Commission sponsorship. Project participants include the Electric Power Research Institute and consortiums from France, Italy, and Japan. This study group has conducted a series of NDE examinations of tubes from a retired-from-service steam generator, using commercially available multifrequency eddy current equipment and ASME procedures. The examination results have been analyzed to identify factors contributing to variations in NDE inspection findings. The reliability of these examinations will then be validated by destructive analyses of the steam generator tubes. The program is expected to contribute to development of a model for steam generator inservice inspection sampling plans and inspection periods, as well as to improved regulatory guidelines for tube plugging. 37143
Shindo, Y.; Yoshie, S.; Morimoto, M.
Quantitative system for evaluating eddy current testing of heat exchanger tubing l l t h World Conference on Nondestructive Testing. Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 122-128. Taylor Publishing Co., Dallas (1985). Eddy current testing (ECT) has played an important role in the inservice inspection of heatexchanger tubing. Performance of a conventional ECT system, however, is mostly limited by hardware and hence data obtained are neither easily transferred to other systems nor optimized for the best defect characterization. A quantitative ECT system has been developed for reliable inspection of tubing in LMFBR (Liquid Metal Fast Breeder Reactor) and VHTR (Very High Temperature Gas-cooled Reactor). An important feature of the system is the acquisition of original eddy current signals in a sampled digital form with little distortion. All the signal processing is done within a computer. Hence its procedures can be precisely specified and optimized. Specifications thus obtained can be transferred to a particular hardware system for field use. 37142
David, B.; Pigeon, M.; Delsarte, G.; Ferre, C.; Levy, R.
Field application of eddy-current data processing l l t h World Conference on Nondestructive Testing. Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 169-177. Taylor Publishing Co., Dallas (1985). Eddy current examination of tubes in PWR steam generators requires a high rate of detection of possible defects. However, due to time considerations it is not possible to perform several tests on the same tube using a different probe each time in order to cover the whole range of potential defects. In the past, the circumferential bobbin coil has been accepted as the best compromise. Signal analysis has been based on phase measurement and the use of phase versus depth calibration curves. The correct use of multifrequency principles allowed the suppression of unwanted signals and a level of confidence in the results of flaw sizing higher than that provided by the use of single frequency. However, the disadvantages of this solution have necessitated the development of new tools in order to meet new requirements. Fundamental studies undertaken by the French Atomic Energy Commission have been adapted to the field and two applications are described in this paper. 37141
Schanne, G.F.
High temperature in eddy current testing of surface defects on steel wire rod during rolling l l t h World Conference on Nondestructive Testing. Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 179-185. Taylor Publishing Co., Dallas (1985). This paper describes eddy current equipment for the nondestructive testing of steel wire rod during hot rolling. 37140
YasuharuHosohara, Tokyo Gas Co., Ltd., Tokyo, Japan
Eddy current probe for buried gas pipe inspection l l t h World Conference on Nondestructive Testing. Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 266-273. Taylor Publishing Co., Dallas (1985). This is a description of the eddy current method for small size gas steel pipe inspection. The effect of magnetization for the detection of flaws on the outside of pipes was investigated. Based on the results, internal probes equipped with electromagnets which can detect corrosion pits on the pipe were designed and fabricated. Test results are also reported. 37139
Krzwosz, K.J. Beissner, R.E. Doherty, J.E.
Pulsed eddy current flaw detection and flaw characterization Electromagnetic Methods of Nondestructive Testing. Edited by William Lord. Nondestructive Testing Monographs and Tracts, Vol. 3, pp. 307- 320. Gordon and Breach Science Publishers (1985). The pulsed eddy current technique is presented as a viable and feasible technique for detection and characterization of small flaws in highly resistive materials such as titanium 6-4. To optimize the flaw detection capability, theoretical models have been used to evaluate the effect of transmitted field as functions of probe geometry. Other investigations included calculations of flaw responses from a given probe with known excitation pulse waveforms. During the course identified for use in the flaw characterization study. Empirical
NDT International June 1989
measurements were taken and compared, where applicable, with the analytical results. In addition, preliminary test results obtained from titanium 6-4 sample pieces containing known flaws are presented in the paper. 37138
de la Pintiere, L.
Multifrequency eddy current examination of heat exchanger tubing Electromagnetic Methods of Nondestructive Testing. Edited by William Lord. Nondestructive Testing Monographs and Tracts, Vol. 3, pp. 195- 305 Gordon and Breach Science Publishers (1985). Preservice inspection of heat exchangers allows detection and correction of manufacturing anomalies, and becomes a reference for future inservice inspections. Periodic inservice inspection allows for monitoring the heat exchanger status evolution and taking early corrective actions. Heat exchangers are commonly tested by eddy current 37137
Deeds, W.E.; Dodd, C.V.
Eddy current inspection of steam generator tubing Electromagnetic Methods of Nondestructive Testing. Edited by William Lord. Nondestructive Testing Monographs and Tracts, Vol. 3, pp. 175- 193. Gordon and Breach Science Publishers (1985). A non-contact rapid inspection method is desirable for the inspection of s~am generator tubing in nuclear reactors. Eddy current test methods appear to the most feasible although the sensitivity of the tests to all sorts of metal variations makes the method vulnerable to unwanted signals from property variations. This article discusses some of the difficulties encountered with eddy current testing of steam generator tubes and outlines the instrumentation required for distinguishing between several types of properties. • 37136
Kostrov, D.S.; Steblev, Y.I.
Design of eddy-current transducers for linear displacements with periodic output characteristics Soviet Journal of Nondestructive Testing, Vol. 22, No. 10, pp. 696-699 (Jun. 1987) The problem of designing the shape of eddy-current transducers for finer displacements in accord with a given periodic output characteristics is discussed. On the basis of a number of well-founded assumptions the solution of the design equations is reduced to a minimization of the functional that is derived by well-known methods of functional analysis. An approximate solution is given for the design equations of eddy-current transducers as well as a numerical solution when a transducer having a linear output characteristic is employed. 37135
Gavrilin, V. V.; Grigulis, Y. K.
Application of the impedance method in constructing eddy-current instruments Soviet Journal of Nondestructive Testing, Vol. 22, No. 10, pp. 690-696 (Jun. 1987) The article contains the fundamentals of the impedance method of eddycurrent quality control. On the basis of the instruments 9f the series VIMP the article presents the results of the use of the theory in devising actual unified eddy-current instruments with improved accuracy and stability. 37134
Goncharov, B. V.; Yanshina, L V.
Problems of the theory of superposed transducers with windings of arbitrary length Soviet Journal of Nondestructive Testing, Vol. 22, No. 10, pp. 685-689 (Jun. 1987) The article presents approximate analytical solutions of problems of eddy-current transducers of the superposed type with windings of arbitrary length. The accuracy of the solutions is verified, the effect of the length of the windings on the output characteristics and selective possibilities of the transducers is determined. The solutions are obtained for single-layer and multilayer objects in the form ofa nonferromagnetic half-space, a ferromagnetic half-space, and a nonferromagnetic plate. 37133
Dood, C. V.; Whitaker, L.M.; Deeds, W.E.
An eddy-current laboratory test system using commercial equipment Oak Ridge National Laboratory, Oak Ridge, Tennessee (United States), ORNL-6366, 124 pp. (Apr. 1987) The combination of a Hewlett Packard impedance analyzer and a laboratory computer has produced a versatile and effective eddy-current laboratory test instrument. This combination has allowed a wide range of eddy-current measurements to be quickly, accurately, and easily performed. Also, this combination has been programmed to make absolute resistivity measurements, multiple-frequency/multiple-property measurements, normalized impedance measurements, and Bode plots (magnitude and phase vs frequency). These measurements are performed for a variety of coil and conductor combinations, including reflection, through transmission, and single-coil configurations. The intelligence of the computer, combined with the ease of operation and programming of the impedance analyzer over the IEEE-488 bus, can make quick work of jobs that formerly took much longer. 37132
Burke, S.K.; Rose, L.R.F.
Eddy-current NDI of cracks in thin plates Journal of Physics D, Vol. 20, No. 6, pp. 797-800 (14 Jan. 1987) A general expression is derived for the change in coil impedance due to a through-crack in a conducting plate when the plate thickness (h) is small compared with the skin-depth (d). Theoretical calculations are presented for the specific case of a circular air-cored coil and a crack which is much longer than the
183
Reliability of eddy current examination of steam generator tubes l l t h World Conference on Nondestructive Testing, Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 162-168. Taylor Publishing Co., Dallas (1985). A unique study of nondestruct'i~,e examination reliability is underway at the Pacific Northwest Laboratory under U.S. Nuclear Regulatory Commission sponsorship. Project participants include the Electric Power Research Institute and consortiums from France, Italy, and Japan. This study group has conducted a series of NDE examinations of tubes from a retired-from-service steam generator, using commercially available multifrequency eddy current equipment and ASME procedures. The examination results have been analyzed to identify factors contributing to variations in NDE inspection findings. The reliability of these examinations will then be validated by destructive analyses of the steam generator tubes. The program is expected to contribute to development of a model for steam generator inservice inspection sampling plans and inspection periods, as well as to improved regulatory guidelines for tube plugging. 37143
Shindo, Y.; Yoshie, S.; Morimoto, M.
Quantitative system for evaluating eddy current testing of heat exchanger tubing l l t h World Conference on Nondestructive Testing. Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 122-128. Taylor Publishing Co., Dallas (1985). Eddy current testing (ECT) has played an important role in the inservice inspection of heatexchanger tubing. Performance of a conventional ECT system, however, is mostly limited by hardware and hence data obtained are neither easily transferred to other systems nor optimized for the best defect characterization. A quantitative ECT system has been developed for reliable inspection of tubing in LMFBR (Liquid Metal Fast Breeder Reactor) and VHTR (Very High Temperature Gas-cooled Reactor). An important feature of the system is the acquisition of original eddy current signals in a sampled digital form with little distortion. All the signal processing is done within a computer. Hence its procedures can be precisely specified and optimized. Specifications thus obtained can be transferred to a particular hardware system for field use. 37142
David, B.; Pigeon, M.; Delsarte, G.; Ferre, C.; Levy, R.
Field application of eddy-current data processing l l t h World Conference on Nondestructive Testing. Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 169-177. Taylor Publishing Co., Dallas (1985). Eddy current examination of tubes in PWR steam generators requires a high rate of detection of possible defects. However, due to time considerations it is not possible to perform several tests on the same tube using a different probe each time in order to cover the whole range of potential defects. In the past, the circumferential bobbin coil has been accepted as the best compromise. Signal analysis has been based on phase measurement and the use of phase versus depth calibration curves. The correct use of multifrequency principles allowed the suppression of unwanted signals and a level of confidence in the results of flaw sizing higher than that provided by the use of single frequency. However, the disadvantages of this solution have necessitated the development of new tools in order to meet new requirements. Fundamental studies undertaken by the French Atomic Energy Commission have been adapted to the field and two applications are described in this paper. 37141
Schanne, G.F.
High temperature in eddy current testing of surface defects on steel wire rod during rolling l l t h World Conference on Nondestructive Testing. Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 179-185. Taylor Publishing Co., Dallas (1985). This paper describes eddy current equipment for the nondestructive testing of steel wire rod during hot rolling. 37140
YasuharuHosohara, Tokyo Gas Co., Ltd., Tokyo, Japan
Eddy current probe for buried gas pipe inspection l l t h World Conference on Nondestructive Testing. Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 266-273. Taylor Publishing Co., Dallas (1985). This is a description of the eddy current method for small size gas steel pipe inspection. The effect of magnetization for the detection of flaws on the outside of pipes was investigated. Based on the results, internal probes equipped with electromagnets which can detect corrosion pits on the pipe were designed and fabricated. Test results are also reported. 37139
Krzwosz, K.J. Beissner, R.E. Doherty, J.E.
Pulsed eddy current flaw detection and flaw characterization Electromagnetic Methods of Nondestructive Testing. Edited by William Lord. Nondestructive Testing Monographs and Tracts, Vol. 3, pp. 307- 320. Gordon and Breach Science Publishers (1985). The pulsed eddy current technique is presented as a viable and feasible technique for detection and characterization of small flaws in highly resistive materials such as titanium 6-4. To optimize the flaw detection capability, theoretical models have been used to evaluate the effect of transmitted field as functions of probe geometry. Other investigations included calculations of flaw responses from a given probe with known excitation pulse waveforms. During the course identified for use in the flaw characterization study. Empirical
NDT International June 1989
measurements were taken and compared, where applicable, with the analytical results. In addition, preliminary test results obtained from titanium 6-4 sample pieces containing known flaws are presented in the paper. 37138
de la Pintiere, L.
Multifrequency eddy current examination of heat exchanger tubing Electromagnetic Methods of Nondestructive Testing. Edited by William Lord. Nondestructive Testing Monographs and Tracts, Vol. 3, pp. 195- 305 Gordon and Breach Science Publishers (1985). Preservice inspection of heat exchangers allows detection and correction of manufacturing anomalies, and becomes a reference for future inservice inspections. Periodic inservice inspection allows for monitoring the heat exchanger status evolution and taking early corrective actions. Heat exchangers are commonly tested by eddy current 37137
Deeds, W.E.; Dodd, C.V.
Eddy current inspection of steam generator tubing Electromagnetic Methods of Nondestructive Testing. Edited by William Lord. Nondestructive Testing Monographs and Tracts, Vol. 3, pp. 175- 193. Gordon and Breach Science Publishers (1985). A non-contact rapid inspection method is desirable for the inspection of s~am generator tubing in nuclear reactors. Eddy current test methods appear to the most feasible although the sensitivity of the tests to all sorts of metal variations makes the method vulnerable to unwanted signals from property variations. This article discusses some of the difficulties encountered with eddy current testing of steam generator tubes and outlines the instrumentation required for distinguishing between several types of properties. • 37136
Kostrov, D.S.; Steblev, Y.I.
Design of eddy-current transducers for linear displacements with periodic output characteristics Soviet Journal of Nondestructive Testing, Vol. 22, No. 10, pp. 696-699 (Jun. 1987) The problem of designing the shape of eddy-current transducers for finer displacements in accord with a given periodic output characteristics is discussed. On the basis of a number of well-founded assumptions the solution of the design equations is reduced to a minimization of the functional that is derived by well-known methods of functional analysis. An approximate solution is given for the design equations of eddy-current transducers as well as a numerical solution when a transducer having a linear output characteristic is employed. 37135
Gavrilin, V. V.; Grigulis, Y. K.
Application of the impedance method in constructing eddy-current instruments Soviet Journal of Nondestructive Testing, Vol. 22, No. 10, pp. 690-696 (Jun. 1987) The article contains the fundamentals of the impedance method of eddycurrent quality control. On the basis of the instruments 9f the series VIMP the article presents the results of the use of the theory in devising actual unified eddy-current instruments with improved accuracy and stability. 37134
Goncharov, B. V.; Yanshina, L V.
Problems of the theory of superposed transducers with windings of arbitrary length Soviet Journal of Nondestructive Testing, Vol. 22, No. 10, pp. 685-689 (Jun. 1987) The article presents approximate analytical solutions of problems of eddy-current transducers of the superposed type with windings of arbitrary length. The accuracy of the solutions is verified, the effect of the length of the windings on the output characteristics and selective possibilities of the transducers is determined. The solutions are obtained for single-layer and multilayer objects in the form ofa nonferromagnetic half-space, a ferromagnetic half-space, and a nonferromagnetic plate. 37133
Dood, C. V.; Whitaker, L.M.; Deeds, W.E.
An eddy-current laboratory test system using commercial equipment Oak Ridge National Laboratory, Oak Ridge, Tennessee (United States), ORNL-6366, 124 pp. (Apr. 1987) The combination of a Hewlett Packard impedance analyzer and a laboratory computer has produced a versatile and effective eddy-current laboratory test instrument. This combination has allowed a wide range of eddy-current measurements to be quickly, accurately, and easily performed. Also, this combination has been programmed to make absolute resistivity measurements, multiple-frequency/multiple-property measurements, normalized impedance measurements, and Bode plots (magnitude and phase vs frequency). These measurements are performed for a variety of coil and conductor combinations, including reflection, through transmission, and single-coil configurations. The intelligence of the computer, combined with the ease of operation and programming of the impedance analyzer over the IEEE-488 bus, can make quick work of jobs that formerly took much longer. 37132
Burke, S.K.; Rose, L.R.F.
Eddy-current NDI of cracks in thin plates Journal of Physics D, Vol. 20, No. 6, pp. 797-800 (14 Jan. 1987) A general expression is derived for the change in coil impedance due to a through-crack in a conducting plate when the plate thickness (h) is small compared with the skin-depth (d). Theoretical calculations are presented for the specific case of a circular air-cored coil and a crack which is much longer than the
183