• 제목/요약/키워드: magnetic probe

검색결과 260건 처리시간 0.024초

Design and Implementation of Portable NMR Probe Magnet

  • Junxia, Gao;Yiming, Zhang;Jiashen, Tian
    • Journal of Magnetics
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    • 제22권1호
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    • pp.14-22
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    • 2017
  • The NMR's probe consists of the static magnetic field generator (magnetic source) and the RF coil. It is very strict for the homogeneity of the static magnetic field intensity of the magnetic source, so the cost of the magnetic source is more expensive in the entire nuclear magnetic resonance instrument. The magnetic source generally consists of electromagnet, permanent magnet and superconducting magnet. The permanent magnet basically needs not to spend on operation and maintenance and its cost of manufacture is much cheaper than the superconducting magnet. Therefore, the permanent magnet may be the only choice for the static magnetic field device if we want to use the magnetic resonance instrument as an analyzer for production by reducing price. A new probe magnet was developed on the basis of the permanent magnet ring in this paper to provide a technological way for reducing the manufacturing cost, weight and volume of the existing nuclear magnetic resonance instrument (including MRI) probe.

Design and embodiment of variableness band style magnetic field nerve stimulation system that apply $1^{trigger}$ $2^{mode}$ magnetic field treatment Probe for disease treatment

  • Kim, Whi-Young;Park, Sung-Joon
    • Journal of information and communication convergence engineering
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    • 제6권4호
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    • pp.411-416
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    • 2008
  • When compose magnetic field curer by belt and band style and need by magnetic field ripple last month, produce self-discipline roof. Bred in muscle disease (lumbago, backbone disease, corpulence) back. Result that study, manufactured various variableness band style - magnetic field probe firstly. Can establish self-discipline treatment pulse price by disease secondly. Could seek correct variableness band punishment, - magnetic field probe relationship implementation and property in waist, and so on, shoulder, neck, arm, leg, ankle, wrist etc. by third. Could find variableness band style energy value that need in-magnetic field Probe's treatment by fourth. This research could design pulse of self-discipline in band form and apply each according to disease.

Near-field Noise-emission Modeling for Monitoring Multimedia Operations in Mobile Devices

  • Song, Eakhwan;Choi, Jieun;Lee, Young-Jun
    • IEIE Transactions on Smart Processing and Computing
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    • 제5권6호
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    • pp.440-444
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    • 2016
  • In this paper, an equivalent circuit model for near-field noise emission is proposed to implement a multimedia operation-monitoring system for mobile devices. The proposed model includes a magnetic field probe that captures noise emissions from multimedia components, and a transfer function for near-field noise coupling from a transmission line source to a magnetic field probe. The proposed model was empirically verified with transfer function measurements of near-field noise emissions from 10 kHz to 500 MHz. With the proposed model, a magnetic field probe was optimally designed for noise measurement on a camera module and an audio codec in a mobile device. It was demonstrated that the probe successfully captured the near-field noise emissions, depending on the operating conditions of the multimedia components, with enhanced sensitivity from a conventional reference probe.

비접촉식 정밀 변위 측정용 자기센서 모델링 (Modeling of a Non-contact Type Precision Magnetic Displacement Sensor)

  • 신우철;홍준희;이기석
    • 한국정밀공학회지
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    • 제22권8호
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    • pp.42-49
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    • 2005
  • Our purpose is to develop a precision magnetic displacement sensor that has sub-micron resolution and small size probe. To achieve this, we first have tried to establish mathematical models of a magnetic sensor in this paper. The inductance model that presents basic measuring principle of a magnetic sensor is based on equivalent magnetic circuit method. Especially we have concentrated on modeling of magnetic flux leakage and magnetic flux fringing. The induced model is verified by experimental results. The model, including the magnetic flux leakage and flux fringing effects, is in good agreement with the experimental data. Subsequently, based on the augmented model, we will design magnetic sensor probe in order to obtain high performances and to scale down the probe.

Hall probe를 이용한 비접촉 임계전류 측정 (Non-contact critical current measurement using hall probe)

  • 김호섭;이남진;하동우;백승규;김태형;고락길;하홍수;오상수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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    • pp.7-8
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    • 2009
  • Non-contact critical current measurement apparatus was developed using hall probe which measures the magnetic field distribution across the width of superconducting tape. The hall probe consists of 7 independent hall sensors which lie in a line 600 ${\mu}m$. The difference between maximum and minimum magnetic field in the magnetic filed distribution is a main parameter to determine the critical current. As preliminary research, we calculated the magnetic field intensity at the middle sensor, which is a minimum magnetic field and generated by the circular shielding current modeled by Bean model. We confirmed that there are some parameters that affect on the minimum magnetic field; the distance between superconducting layer and hall sensor, the width of superconducting tape, and the critical current distribution across the width of superconducting tape. Among these parameters, the distance between superconducting layer and hall sensor highly influences on the minimum magnetic field.

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Hall Probe를 이용한 초전도선재의 비접촉 임계전류 측정 방법 (Non-contact critical current measurement of superconducting coated conductor using Hall Probe)

  • 김호섭;오상수;이남진;하동우;백승규;고락길;하홍수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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    • pp.12-12
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    • 2010
  • The hall probe measurement system was used to measure the critical current distribution of superconducting coated conductor. The system consists of reel to reel moving apparatus, 7 array hall probe, a rotary encoder and permanent magnet. The magnetic field profile across the width of superconducting coated conductor using Bean's critical state model was calculated. The effect of various parameters of the formulas on the magnetic field distribution and the effect of shape and size of artificial defects, which were formed on the surface of SmBa2Cu3O7-d(SmBCO) coated conductor using laser marking system, on the hall probe magnetic field signal of the hall probe measurement system was investigated.

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Development of Micro-size Search Coil Magnetometer for Magnetic Field Distribution Measurement

  • Ka, E.M.;Son, De-Rac
    • Journal of Magnetics
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    • 제13권1호
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    • pp.34-36
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    • 2008
  • For the measurement of the magnetic field distribution with high spatial resolution and high accuracy, the magnetic field sensing probe must be non-magnetic, but the MFM probe and sub-millimeter-meter size Hall probe use a ferromagnetic tip and block, respectively, to increase the sensitivity. To overcome this drawback, we developed a micro-size search coil magnetometer which consists of a single turn search coil, Terfenol-D actuator, scanning system, and control software. To reduce the noise generated by the stray ac magnetic field of the actuator driving coil, we employed an even function $\lambda$-H magnetostriction curve and lock-in technique. Using the developed magnetometer, we were able to measure the magnetic field distribution with a magnetic field resolution of 1 mT and spatial resolution of $0.1mm{\times}0.2mm$ at a coil vibration frequency of 1.8 kHz.

시변 펄스형 자기장 의료기기 시스템 (Development of Medical System using Time-varying Magnetic field)

  • 김인수;홍정환
    • 한국정보통신학회논문지
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    • 제11권12호
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    • pp.2343-2351
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    • 2007
  • 본 논문은 시변 펄스형 자기장(Time-varying Magnetic field)을 반복적으로 발생시키는 전원장치 및 전원장치에서 발생된 에너지를 자기장으로 발생키시기 위한 자기유도 코일 probe의 설계 및 구현을 통하여 짧은 시간($300{\mu}s$이하) 동안 고자기장(${\sim}1.2Tesla$)을 발생시켰다. 시간과 펄스 주기를 순차적으로 조정 할 수 있는 다단 메쉬 방식으로 설계하여 고반복적($0.1Hz{\sim}20Hz$)으로 스위칭했을 경우에도 동일한 출력세기를 발생시킬 수 있는 자기장 의료기기 시스템을 구현하였다.

자기 탐침에 의한 쎄타 핀치 플라즈마의 진단 (Diagnostics of Theta-Pinch Plasma by Magnetic Probe)

  • 심재학;조주현;장용무;정운관;강형부
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1989년도 하계종합학술대회 논문집
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    • pp.401-404
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    • 1989
  • Some magnetic probes for theta-pinch experiment have been constructed. Methods of building the coil, conecting it to the oscilloscope, shielding and enclosing the probe are discribed. Such a probe has been used to measure the magnetic flux penetrating it within theta - pinched plasmas.

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발전기 정지중 진단을 위하여 개발된 유도결합 마그네틱 프로브의 성능특성 (Performance Characteristics of an Inductively Coupled Magnetic Probe Developed for Off-line Monitoring of a Rotating Machine)

  • 박노준;양상현;공태식;김희동;박대희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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    • pp.46-46
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    • 2010
  • In order to detect exact corona discharge point at stator winding of a rotating machine, an inductively coupled magnetic probe has been developed, which consists of U-shaped and truncated manganese ferrite inductor as a helix. The measured current intensity is somewhat higher than commercially developed probe. It has been shown that the measured intensity of proposed probe is suitable for manual localization as to off-line stator winding monitoring of rotating machine.

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