• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.10 no.1
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• pp.75-81
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• 2014

A simulation of eddy current testing has been utilized for predicting the signal characteristics to the various defects and developing the probes. Especially, CIVA which is a simulation tool dedicated to nondestructive testing has a good accuracy and speed, and provides a three-dimensional graphical user interface for improved visualization and familiar data displays consistent with NDE technique. Although internal validations have been performed by the CIVA software development specialists, an independent validation study is necessary for the accuracy assessment of the software prior to practical use. For this purpose, in this study, eddy current testing signals of ASME FBH calibration standard tube for bobbin probe were simulated using CIVA and the results were compared to the experimental inspected signals based on the relationship between each flaw signal in terms of amplitude and phase, and the shape of the Lissajous curve. And then we verified the accuracy of the simulated signals and the possible range for simulation. Overall, there is a good qualitative agreement between the CIVA simulated and experimental results in the absolute and differential modes at the two inspection frequencies.

• Journal of Magnetics
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• v.16 no.3
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• pp.276-280
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• 2011

This paper presents a non-destructive evaluation study on a radiator with cooling fins as a complex shaped specimen. Radiator structures are used in various heat exchangers, such as automobiles, air conditioners and refrigerators. An eddy current testing method, namely multi-frequency excitation and spectrogram method (MFES), was employed to detect a defect on the radiator tube surrounded by cooling fins. Overall, experimental results suggested that the influence of cooling fin is not as noticeable as that of the defect signals.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.11
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• pp.1434-1444
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• 1995

Current test has recently been known to be a promising testing method in CMOS VLSI because conventional voltage test can not make sure of the complete detection of bridging, gate-oxide shorts, stuck-open faults and etc. This paper presents a new BIC(built-in current sensor) for the internal current test in CMOS logic circuit. A single phase clock is used in the BIC to reduce the control circuitry of it and to perform a self- testing for a faulty current. The BIC is designed to detect the faulty current at the end of the clock period, so that it can test the CUT(circuit under test) with much longer critical propagation delay time and larger area than conventional BICs. The circuit is composed of 18 devices and verified by using the SPICE simulator.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.321-329
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• 2012

Providing variable load for testing a motor in high speed conditions is usually a difficult task. The eddy current brake can be used in application of load testing of motors. This paper deals with construction of a novel claw pole eddy current brake which is employed as a load for a DC counter rotating motor (CRM). These kinds of motors have two inner and outer shafts that rotate in opposite directions simultaneously, which are particularly suitable for under water propulsion systems. The prototype 45KW eddy current brake consists of two parts. One of them is installed on the inner shaft of the 60KW DC CRM and the other one is installed on its outer shaft. The simulation and experimental results with prototype brakes are also analyzed by using MATLAB/Simulink and the operational characteristic of the brake is demonstrated as a function of the motor speed and current of the magnetic poles.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.5
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• pp.465-471
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• 2013

A steam generator in nuclear power plant is a heatexchager which is used to convert water into steam from heat produced in a nuclear reactor core, and the steam produced in steam generator is delivered to the turbine to generate electricity. Because of damage to steam generator tubing may impair its ability to adequately perform required safety functions in terms of both structural integrity and leakage integrity, eddy current testing is periodically performed to evaluate the integrity of tubes in steam generator. This assessment is normally performed during a reactor refueling outage. Currently, the eddy current testing for steam generator of nuclear power plant in Korea is performed in accordance with KEPIC & ASME Code requirements, the eddy current testing system is consists of remote data acquisition unit and data analysis program to evaluate the acquired data. The KEPIC & ASME Code require that the electrical properties of remote data acquisition unit, such as total harmonic distortion, input & output impedance, amplifier linearity & stability, phase linearity, bandwidth & demodulation filter response, analog-to-digital conversion, and channel crosstalk shall be measured in accordance with the KEPIC & ASME Code requirements. In this paper, the measurement requirements of electrical properties for eddy current testing instrument described in KEPIC & ASME Code are presented, and the measurement results of newly developed eddy current testing instrument by KHNP(Korea Hydro & Nuclear Power Co., LTD) are presented.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.2
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• pp.94-100
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• 1993

이번 호부터 해설란을 통하여 비파괴검사(非破壞檢査) 기술(技術)에 대한 연재를 시작한다. 앞으로 비파괴검사(非破壞檢査) 기술(技術) 각 분야에 대해 다룰 예정이며 우선 1차적으로 와전류탐상법(渦電流探傷法)에 관해 3회에 걸쳐 게재하기로 한다. 특정한 비파괴검사(非破壞檢査)의 전문가가 아니더라도 쉽게 이해할 수 있도록 가급적 수식은 배제하고 기초적인 이론을 소개할 것이며 특히 현장 적용에 중점을 두어 기술(記述)하고자 한다. 본 원고에서는 원거리 와전류탐상법(渦電流探傷法)(remote field eddy current testing) 이나 펄스 와전류탐상법(渦電流探傷法)(pulsed eddy current testing)과 같은 특수 와전류(渦電流) 기술(技術)은 제외하였으며 본 연구실에서 내부 교육용으로 사용하는 "와전류탐상법(渦電流探傷法) Level I 과정"과 미국금속학회에서 발행한 Metal Handbook, 9th ed., Vol. 17, "Non-destructive Evaluation and Quality Control" 및 기타 관련 기술 자료들을 참고하였으나 일일이 명기하지는 않는다.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.3
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• pp.255-261
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• 2007

By using numerical analysis methods, through transmission type pulsed eddy current (PEC) testing is modeled and PEC signal responses due to varying material conductivity, permeability, thickness, lift-off and pulse width are investigated. Results show that the peak amplitude of PEC signal gets reduced and the time to reach the peak amplitude is increased as the material conductivity, permeability, and specimen thickness increase. Also, they indicate that the pulse width needs to be shorter when evaluating the material conductivity and the plate thickness using the peak amplitude, and when the pulse width is long, the peak time is found to be more useful. Other results related to lift-off variation are reported as well.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.4
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• pp.47-56
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• 1994

지난 호에 이어 해설란을 통하여 비파괴검사(非破壞檢査) 기술(技術)에 대한 연재를 계속한다. 특정한 비파괴검사(非破壞檢査)의 전문가가 아니더라도 쉽게 이해할 수 있도록 가급적 수식은 배제하고 기초적인 이론을 소개할 것이며 특히 현장 적용에 중점을 두어 기술(技術)하고자 한다. 본 원고에서는 원거리 와전류탐상법(渦電流探傷法(remote field eddy current testing) 이나 펄스 와전류탐상법(渦電流探傷法(pulsed eddy current testing)과 같은 특수 와전류(渦電流) 기술(技術)은 제외하였으며 본 연구실에서 내부 교육용으로 사용하는 "와전류탐상법(渦電流探傷法) Level I 과정"과 미국금속학회에서 발행한 Metal Handbook, 9th ed., Vol. 17, "Nondestructive Evaluation and Quality Control" 및 기타 관련 기술 자료들을 참고하였으나 일일이 명기하지는 않는다.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.3
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• pp.39-45
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• 1993

지난 호에 이어 해설란을 통하여 비파괴검사(非破壞檢査) 기술(技術)에 대한 연재를 계속한다. 특정한 비파괴검사(非破壞檢査)의 전문가가 아니더라도 쉽게 이해할 수 있도록 가급적 수식은 배제하고 기초적인 이론을 소개할 것이며 특히 현장 적용에 중점을 두어 기술(技術)하고자 한다. 본 원고에서는 원거리 와전류탐상법(渦電流探傷法(remote field eddy current testing) 이나 펄스 와전류탐상법(渦電流探傷法(pulsed eddy current testing)과 같은 특수 와전류(渦電流) 기술(技術)은 제외하였으며 본 연구실에서 내부 교육용으로 사용하는 "와전류탐상법(渦電流探傷法) Level I 과정"과 미국금속학회에서 발행한 Metal Handbook, 9th ed., Vol. 17, "Nondestructive Evaluation and Quality Control" 및 기타 관련 기술 자료들을 참고하였으나 일일이 명기하지는 않는다.

• Proceedings of the KWS Conference
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• 2008.05a
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• pp.15-15
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• 2008