• Title, Summary, Keyword: Electric probe

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Characterization of Probe Pin for LED Inspection System (LED 검사장비용 탐침의 특성 규명)

  • Shim, Hee-Soo;Kim, Sun Kyoung
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.24 no.6
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    • pp.647-652
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    • 2015
  • A probe pin is a key component of LED inspection equipment. The probe pin makes contact with the LED electrodes and supplies an electric current. Because the mechanical and electrical homogeneity of the probe surface affects the service life and reliability, its characterization is essential. For this study, the hardness was measured using a micro-Vickers hardness test. Moreover, the thicknesses of the plating at different locations and the elemental compositions were examined using an FE-SEM. The uniformity of the plating was found to be acceptable because palladium was detected consistently throughout the tested domain. In addition, the hardness of the surface was determined to be higher than that of the typical palladium range, which is attributed to the use of undercoated nickel.

Implementation of an Inductively Coupled EM Probe System for PD Diagnosis

  • Kim, Hee-Dong;Park, Noh-Joon;Park, Dae-Hee
    • Journal of Electrical Engineering and Technology
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    • v.6 no.1
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    • pp.111-118
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    • 2011
  • In recent years, various types of partial discharge (PD) methods such as capacitive, inductive, electromagnetic, and acoustic coupling techniques have been developed for diagnosing rotating machines. An electromagnetic (EM) probe, which is an inductively coupled type of sensor, is required for detecting corona and internal discharges during off-line tests. In this study, a new technique for enhancing the measurement sensitivities for corona and internal discharge based on an EM inductive position sensor is proposed. An EM probe that winds wires around horseshoe-shaped and cylindershaped ferrites as helices is designed and optimized for the implementation of off-line PD monitoring of the stator winding of a rotating machine. The measurement system based on this design is implemented, and it is verified from the results of the experiment performed in this study that the probe provides similar performance as existing commercial products.

A Brief Comment on Atom Probe Tomography Applications

  • Seol, Jae-Bok;Kim, Young-Tae;Park, Chan-Gyung
    • Applied Microscopy
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    • v.46 no.3
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    • pp.127-133
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    • 2016
  • Atom probe tomography is a time-of-flight mass spectrometry-based microanalysis technique based on the field evaporation of surface atoms of a tip-shaped specimen under an extremely high surface electric field. It enables three-dimensional characterization for deeper understanding of chemical nature in conductive materials at nanometer/atomic level, because of its high depth and spatial resolutions and ppm-level sensitivity. Indeed, the technique has been widely used to investigate the elemental partitioning in the complex microstructures, the segregation of solute atoms to the boundaries, interfaces, and dislocations as well as following of the evolution of precipitation staring from the early stage of cluster formation to the final stage of the equilibrium precipitates. The current review article aims at giving a comment to first atom probe users regarding the limitation of the techniques, providing a brief perspective on how we correctly interprets atom probe data for targeted applications.

Electrical Measurement of SOx Dew Point (SOx노점의 전기적 측정)

  • Chun, Y.N.;Yong, K.J.;Chae, J.O.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.4
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    • pp.600-610
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    • 1995
  • When combustion gas is cooled down below the dew point of sulfuric acid vapor in the heat recovery systems, condensation occurs. Since the condensed sulfuric acid solution causes low-temperature corrosion in materials, it is important to measure the SOx dew point by electric measurement. In this study, two kinds of probes having electric gaps of 1mm or 2mm were used. and experiments were carried out by the parameters of sulfuric acid vapor and water vapor concentration. The changes of electric current caused by sulfuric acid condensed on the surface of probe according to the cooling rate and the probe head surface temperature were sudied. The opimum cooling rate was decreased with the increasing of water vaper concentration regardless of sulfuric acid concentration. The sensitivity of electric current is improved for the narrower gap(1mm) of ring electrodes, but it rarely affects the SOx dew point measuring of different probes according to the change of cooling rate.

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Coupling Structures in Combline Resonators (Combline 공진기 내의 결합구조)

  • 김병욱;김영수
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • pp.361-365
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    • 2002
  • Three types of the coupling structures in combline resonators are presented: magnetic, electric, and mixed coupling structures. The magnetic coupling structure is provided by the window, and the electric coupling is provided by the electric probe. The mixed coupling structure which is the superposition of the magnetic and electric coupling structures, is proposed for the electric coupling in combline resonators with easy tuning capability. The responses of each coupling structure are shown. A 4-pole combline filter is designed and fabricated as an application of those coupling structures, and shows good filter responses.

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Numerical Analysis for Conductance Probes, for the Measurement of Liquid Film Thickness in Two-Phase Flow

  • No, Hee-Cheon;F. Mayinger
    • Proceedings of the Korean Nuclear Society Conference
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    • pp.450-455
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    • 1995
  • A three-dimensional numerical tool is developed to calculate the potential distribution, electric field, and conductance for any types of conductance probes immersed in the wavy liquid film with various shapes of its free surface. The tool is validated against various analytical solutions. It is applied to find out the characteristics of the wire-wire probe, the flush-wire probe and the flush-flush probe in terms of resolution, linearity, and sensitivity. The wire-wire probe shows high resolution and excellent linearity for various film thickness, but comparably low sensitivity for low film thickness fixed. The flush-wire probe shows good linearity and high sensitivity for varying film thickness, but resolution degrading with an increase in film thickness. In order to check the applicability of the three types of probes in the real situation, the Korteweg-de Vries(KdV) two-dimensional solitary wave is simulated. The wire-wire probe is strongly affected by the installation direction of the two wires; when the wires are installed perpendicularly to the flow direction, the wire-wire probe shows large distortion of the solitary wave. In order to measure the transverse profile of waves, the wire-wire probes and the flush-wire probes are required to be separately installed 2mm and 2mm, respectively.

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Development of On line Diagnosis System for Generator (발전기 운전중 종합 진단시스템 개발)

  • Lee, Young-Jun;Kong, Tae-Sik;Kim, Hee-Dong;Ju, Young-Ho
    • Proceedings of the KIEE Conference
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    • pp.975-977
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    • 2005
  • The generator on-line diagnosis system has been developed. This system monitor the insulation condition of stator winding by on-line measurements of partial discharge and the shorted-turn condition of rotor winding by on-line measurements of slot leakage flux. Sensor, such as SSC(Stator Slot Coupler) and flux probe are used for generator on-line diagnosis.

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A new, hybrid, heterodyne, fiber-optic electric field sensor scheme and its applications (I/Q 변조 풀이 방식의 헤테로다인 간섭계를 이용한 미소 전기장 및 복굴절 측정)

  • 윤신영;조규만;이용산
    • Korean Journal of Optics and Photonics
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    • v.8 no.2
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    • pp.161-164
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    • 1997
  • A new hybrid, heterodyne, fiber-optic electric field sensor scheme is presented. In this scheme, a dual polarization, dual frequency, stabilized He-Ne laser is used for the light source of the interferometer, Probe beam is delivered to the sensor head using polarization maintaining fiber. In the sensor head, $LiTaO_3$ electro-optic crystal is used for sensing element. Phase retardation is induced on the dual frquency, dual polarization probe beam due to applied electric field across the crystal. Induced phase retardation is demodulated by in-phase and quadrature demodulation technique. In this way, we can obtain optimum sensitivity for electric field measurement regardless a quasi-static phase difference between two polarization components.

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Simulation of a Langmuir Probe in an ECR Reactor (ECR Reactor 내의 Langmuir Probe 시뮬레이션)

  • Kim, Hoon;Porteous, Robert K.;Boswell, Rod W.
    • Proceedings of the KIEE Conference
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    • pp.1609-1611
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    • 1994
  • In ECR and helicon reactors for plasma processing, a high density plasma is generated in a source region which is connected to a diffusion region where the processing takes place. Large density and potential gradients can develop at the orifice of the source which drive ion currents into the diffusion region. The average ion velocity may become the order of the sound velocity. Measurements of the ion saturation current to a Langmuir probe are used as a standard method of determining the plasma density in laboratory discharges. However, the analysis becomes difficult in a steaming plasma. We have used the HAMLET plasma simulator to simulate the ion flow to a large langmuir probe in an ECR plasma. The collection surface was aligned with the Held upstream, normal to the field, and downstream. ion trajectories through the electric and magnetic fields were calculated including ion-neutral collisions. We examines the ratio of ion current density to plasma density as a function of magnetic field and pressure.

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A development of $LiNbO_3$ probe sensor for detecting partial discharge (부분방전 전계 측정용 $LiNbO_3$ 프루브 센서 제작)

  • Kang, W.J.;Chang, Y.M.;Koo, J.Y.
    • Proceedings of the KIEE Conference
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    • pp.1041-1043
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    • 1999
  • In this work, a possible new PD detection technique, based on the electro-optic effect, has been proposed. A proto-type probe sensor for detection partial discharge is made by $LiNbO_3$ Pockels cell, diachroic sheet polarizer and right-angle prism. The Mach-Zehnder interferometer system is proposed by using this sensor and this system is applied to detecting high electric field. we show the characteristic of the proto-type probe sensor and the design of a proposed probe type sensor.

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