• Title/Summary/Keyword: Magnetic probe

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Design and Implementation of Portable NMR Probe Magnet

  • Junxia, Gao;Yiming, Zhang;Jiashen, Tian
    • Journal of Magnetics
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    • v.22 no.1
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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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    • v.6 no.4
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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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    • v.5 no.6
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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.

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

  • Shin, Woo-Cheol;Hong, Jun-Hee;Lee, Kee-Seok
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.8 s.173
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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.

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

  • Kim, Ho-Sup;Lee, Nam-Jin;Ha, Dong-Woo;Baik, Seung-Kyu;Kim, Tae-Hyung;Ko, Rock-Kil;Ha, Hong-Soo;Oh, Sang-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.05a
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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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Non-contact critical current measurement of superconducting coated conductor using Hall Probe (Hall Probe를 이용한 초전도선재의 비접촉 임계전류 측정 방법)

  • Kim, Ho-Sup;Oh, Sang-Soo;Lee, Nam-Jin;Ha, Dong-Woo;Baik, Seung-Kyu;Ko, Rock-Kil;Ha, Hong-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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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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    • v.13 no.1
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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.

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

  • Kim, In-Soo S.;Hong, Jung-Hwang
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.12
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    • pp.2343-2351
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    • 2007
  • In this paper, we describe the design and implementation of time-varying magnetic field stimulator. Novel design for power supply part to generate high repetitive magnetic field for very short time(less than $300{\mu}s$) was achieved. Using the novel designed power supply part and the circular type coil probe, we've achieved high magnetic field up to 1.2 Tesla in 20Hz repetition rate.

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

  • Shim, J.H.;Cho, J.H.;Chang, Y.M.;Chung, W.K.;Kang, H.B.
    • Proceedings of the KIEE Conference
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    • 1989.07a
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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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Performance Characteristics of an Inductively Coupled Magnetic Probe Developed for Off-line Monitoring of a Rotating Machine (발전기 정지중 진단을 위하여 개발된 유도결합 마그네틱 프로브의 성능특성)

  • Park, Noh-Joon;Yang, Sang-Hyun;Kong, Tae-Sik;Kim, Hee-Dong;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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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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