• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.968-974
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• 2004

Automakers have been forcing their suppliers to guarantee qualities of parts. Then, the suppliers have met the fundamental quality requirements such as dimensions and functions, but they could not sufficiently satisfy the automakers' noise requirements yet because automatic noise inspection systems were little successfully adopted In mass-production lines. This study tried to develop a system for automatically checking noise radiated from a rotating engine part and filtering parts emitting noise higher than criteria: the upper limits of a overall noise level or a noise spectrum. A commercial noise measurement system was used for measuring noise, and then the noise data was transmitted to a governing program through OLE(object, linking and embedding) functions. The governing program, belonging to a total noise inspection system managed the noise measurement and analysis. This system was successfully adapted for distinguishing bad parts according to the noise criteria.

• Journal of IKEEE
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• v.25 no.3
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• pp.485-492
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• 2021

In this paper, we propose the development of a defect inspection system for polygonal containers. Embedded board consists of main part, communication part, input/output part, etc. The main unit is a main arithmetic unit, and the operating system that drives the embedded board is ported to control input/output for external communication, sensors and control. The input/output unit converts the electrical signals of the sensors installed in the field into digital and transmits them to the main module and plays the role of controlling the external stepper motor. The communication unit performs a role of setting an image capturing camera trigger and driving setting of the control device. The input/output unit converts the electrical signals of the control switches and sensors into digital and transmits them to the main module. In the input circuit for receiving the pulse input related to the operation mode, etc., a photocoupler is designed for each input port in order to minimize the interference of external noise. In order to objectively evaluate the accuracy of the development of the proposed polygonal container defect inspection system, comparison with other machine vision inspection systems is required, but it is impossible because there is currently no machine vision inspection system for polygonal containers. Therefore, by measuring the operation timing with an oscilloscope, it was confirmed that waveforms such as Test Time, One Angle Pulse Value, One Pulse Time, Camera Trigger Pulse, and BLU brightness control were accurately output.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.4
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• pp.258-267
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• 2015

Eddy current testing is widely used for inspecting steam generator tubing in nuclear power plants (NPPs). The inspection technique for steam generator tubing in NPPs should be qualified in accordance with examination guidelines. When the components of a qualified system such as eddy current tester, probe, and data analysis program, are changed, the equivalency of the modified system to the originally qualified system must be verified. The eddy current tester is the most important part of an eddy current testing system because it excites and transmits alternating currents to the probe, receives coil impedance of the probe and generates signals for anomalies. The Korea Hydro & Nuclear Power Co., Ltd. (KHNP) developed an eddy current testing system with an eddy current tester and data acquisition-analysis program for inspecting the steam generator tubing in NPPs; this system can be used for an array probe and as a bobbin and rotating probes. The equivalency assessment for the currently developed system was carried out, and we describe the results in this paper.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.3
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• pp.61-66
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• 2011

The integrity of the SG(Steam Generator) tubes has been challenged by numerous factors such as flaws, operation, atmosphere, inherently degraded materials, loose parts and even human errors. Of the factors, loose parts(or foreign materials) on the secondary side of the tubes can bring about volumetric defects and even leakage from the primary to the secondary side in a short period of time. More serious concerns about the loose parts are their unknown influx path and rapid growth rate of the defects affected by the loose parts. Therefore it is imperative to detect and characterize the foreign materials and the defects. As a part of the measures for loose part detection, TTS(Top of Tubesheet) MRPC(Motorized Rotating Pancake Coils) ECT has been carried out especially to the restricted high probability area of the loose part. However, in the presence of loose parts in the other areas, wide range loose part detection techniques are required. In this study, loose part standard tube was presented as a way to accurately detect and characterize loose part signals. And the SG tube ECT bobbin coil and MRPC ISI(In-service Inspection) data of domestic OPR-1000 and Westinghouse Model F(W_F) were reviewed and consequently, comprehensive loose part detection technique is derived especially by applying bobbin coil signals