• 제목/요약/키워드: magnetic field measurement

검색결과 518건 처리시간 0.033초

평등자계 형성용 전자석 자극 구조에 관한 연구 (Magnetic Pole Structure of Electro-Magnet for Forming Uniform Magnetic Field)

  • 김정태;이승면;조현준;김훈년
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
    • /
    • pp.515-518
    • /
    • 2002
  • In this study, the ellipsoidal cap type magnetic pole structure was proposed for the electro-magnet in B-H curve tracer. From the simulation for the electro-magnet without specimen, the area of effective uniform field(99% range for the central field value) was considerably increased in case of the newly proposed ellipsoidal cap type magnetic pole than that of the conventional simple-inclined cap type magnetic pole. Also, through the simulation for the electro-magnet with permanent magnet specimen(NaFe30), the optimal Positions of the magnetic field measurement sensor(Hall sensor) were found out in each case and the errors were decreased in case of the newly proposed ellipsoidal cap type magnetic pole.

  • PDF

Establishment of the Measurement System of the Magnetic Field for the Study on the Magnetic Field Tolerance of TMP

  • Baik, Kyungmin;Cheung, Wan-Sup;Lim, Jong-Yeon;Choi, Kyoung-Min;Nam, Seung-Hwan
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
    • /
    • pp.106.1-106.1
    • /
    • 2013
  • When strong static magnetic field is applied to the TMP, it is expected that the presence of the magnetic field might retard the velocity of the blades which results in the change of the pumping speed of the TMP. However, such effect of the magnetic field on the TMP has not been well characterized. Thus, under the strong magnetic field, monitoring pumping speed as well as generated heat, pressure, and vibration of the TMP may be an important issue to understand the magnetic field tolerance of the TMP and the development of magnetic shielding technique for the key components of the pump. For this purpose, magnetic field generation system to the vertical direction by a circular current source was firstly designed and suggested [K. Baik et al., 44th Annual Conf. KVS, 22(1), 153, (2012)]. In the current study, another magnetic field generation systems are presented to apply the magnetic field to the horizontal and radial directions by the rectangular current sources and the permanent magnets respectively. Such systems were made to generate at least 50 Gauss of magnetic field along the vertical direction and at least 25 Gauss of magnetic field along the horizontal or radial direction. Current study introduces the evaluation system of the magnetic field along the vertical, horizontal, and radial directions and presents the measured experimental results of the magnetic field when such systems are combined with the equipment where TMP will be installed.

  • PDF

UKF를 사용한 AHRS의 자기장 측정 편차 추정 (Bias Estimation of Magnetic Field Measurement by AHRS Using UKF)

  • 고낙용;송경섭;정석기;이종무;최현택;문용선
    • 한국해양공학회지
    • /
    • 제31권2호
    • /
    • pp.177-182
    • /
    • 2017
  • This paper describes an unscented Kalman filter approach to estimate the bias in magnetic field measurements. A microelectromechanical systems attitude heading reference system (MEMS AHRS) was used to measure the magnetic field, together with the acceleration and angular rate. A magnetic field is usually used for yaw detection, while the acceleration serves to detect the roll and pitch. Magnetic field measurements are vulnerable to distortion due to hard-iron effect and soft-iron effect. The bias in the measurement accounts for the hard-iron effect, and this paper focuses on an approach to estimate this bias. The proposed method is compared with other methods through experiments that implement the navigation of an underwater robot using an AHRS and Doppler velocity log. The results verify that the compensation of the bias by the proposed method improves the navigation performance more than or comparable to the compensation by other methods.

전력구 내 전자기파에 대한 작업 환경 측정 (The Measurement of Electromagnetic Wave in Power Cable Tunnel of Underground Utility Tunnel)

  • 강대곤;박재학
    • 한국안전학회지
    • /
    • 제34권1호
    • /
    • pp.1-7
    • /
    • 2019
  • Electromagnetic measurements of the power cable tunnel were conducted from August 10 to 20, 2018, in the ${\bigcirc}{\bigcirc}$ city underground utility tunnel. During this period, the average temperature was $31.89^{\circ}C$ and the humidity was 67.56% in power cable tunnel. As a result of the electromagnetic measurement, the highest electric field was 25.3 V/m and the magnetic flux density was $42.6{\mu}T$. The average electric field was 18.56 V/m and the magnetic flux density was $29.32{\mu}T$ in the power cable tunnel. As a result of comparison with the electric equipment technical standard, the electric field in the power cable tunnel was 0.5% of the electric equipment standard and 35.2% of the magnetic flux density. It's similar value that electric field is about robotic vacuum(15.53 V/m), and magnetic flux density is similar value about capsule- type coffee machine ($23.07{\mu}T$). The number of cable lines and the size of the electromagnetic waves were not proportional to each other through comparison of cable lines in the power cable tunnel. It was confirmed that 154 kV, rather than 22.9 kV, could have a greater influence on occupational.

저압방전등의 사용중에 발생하는 자계특성 (Characteristics of Magnetic Field Generated by Operating Low Pressure Discharge Lamp)

  • 이복희;전덕규;길경석;백용현
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1994년도 춘계학술대회 논문집
    • /
    • pp.63-66
    • /
    • 1994
  • This paper describes the developed sensor for measuring the time-varying magnetic fields and presents the characteristics of the magnetic fields and presents the characteristics of the magnetic field generated by lighting a fluorescent lamp. The frequency bandwidth of magnetic field measurement system is kknown as 40 Hz∼100 kHz by means of calibration experiment. The magnetic field waveform which originates from the various lighting systems was measured and the frequency components were analyzed by fast Fourier transformation technique. The magnetic field generated during the operation of the fluorescent lamp mainly includes the odd harmonics, and in the case\ulcorner of push button switch and high frequency starter types the fast transient component is occurred in an instant of lighting.

  • PDF

비자성 배관의 비접촉 굽힘 진동 측정을 위한 자기 센서의 개발 (A new magnetic sensor for the non-contact measurement of bending vibrations of non-ferromagnetic pipes)

  • 한순우;김윤영
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2006년도 춘계학술대회논문집
    • /
    • pp.1154-1158
    • /
    • 2006
  • This investigation suggests a new non-contact type sensor that can measure flexural vibrations of a non-ferromagnetic pipe. The sensor works on the reversed Lorentz force mechanism; however, anti-symmetric bias magnetic field suggested in this work should be applied to measure bending vibration of a non-ferromagnetic pipe. The importance of the suggested magnetic field is verified by a series of experiments. The sensor is applied to the bending vibration measurement and modal testing of an aluminum pipe and shows satisfactory working performance compared to others.

  • PDF

SSFPI 기법을 이용한 MR 뇌기능 영상 -고 속의 자화율 효과의 직접적인 측정 (SSFP Interferometry (SSFPI) Technique Applied to functional MRI - A Fast and Direct Measurement of Magnetic Susceptibility Effect)

  • 정준영
    • 대한의용생체공학회:의공학회지
    • /
    • 제17권4호
    • /
    • pp.525-534
    • /
    • 1996
  • We have developed a fast steady state free precession interferometry (SSFPI) technique which is useful for the fMRl (functional Magnetic Resonance Imaging). As is known, SSFP sequence with a suitable adjustment of Vadient (readeut) allows us to measure precession angle 6 which in tw relates to the field inhomogeneity. Combining the two pulses (known as FID and Echo) in FADE (Fast Acquisition Double Echo) sequence, for example, one can obtain the interference term which is directly related to the precession angle It has been known that a fast high resolution magnetic field mapping is possible by use of the modified FADE sequence or SSFPI, and we have attempted to use the SSFPI technique for the susceptibility-induced fMRl. When the method is applied to the susceptibility effect based functional magnetic resonance imaging (fMRl), it was found that the direct susceptibility effect measurement was possible without perturbations such as the backgrounds and inflow effect. In this paper, simulation results and experimental results obtained with 2.0 Tesla MRI system are presented.

  • PDF

22.9[kV] 배전선로 주변의 전장과 자장의 분포 (Profiles of Electric and Magnetic Fields around 22.9[kV] Distribution Lines)

  • 이복희;;박종순;길형준
    • 한국조명전기설비학회지:조명전기설비
    • /
    • 제13권2호
    • /
    • pp.178-178
    • /
    • 1999
  • In recent years, the electromagnetic environments are varied with the increase of power consumption and the spread of household electric appliances. Most of the interests to date have concentrated in the area of human health effects associated with exposure to power frequency electric and magnetic fields, and thus the precise measurement and analysis are required. In this paper, the measurements and analysis of the extremely low frequency(ELF) electric and magnetic fields produced by actual 22.9[kV] distribution lines were performed. The experiments have been carried out by lateral profile, and the theoretical analyses were made by use of FIELDS program for the sate of comparison with the experimental data. Electric and magnetic field intensity were strong under power distribution lines, and were inversely proportional to lateral distance. The profiles of electric and magnetic fields were M and ∩ shapes, respectively, and the measured data were good in agreement with the theoretical results. Both the electric and magnetic field intensity were increased with increasing the measurement height.

PRELIMINARY REPORT: DESIGN AND TEST RESULTS OF KSR-3 ROCKET MAGNETOMETERS

  • Kim, Hyo-Min;Jang, Min-Hwan;Lee, Dong-Hun;Ji, Jong-Hyun;Kim, Sun-Mi;Son, De-Rac;Hwang, Seung-Hyun
    • Journal of Astronomy and Space Sciences
    • /
    • 제17권2호
    • /
    • pp.317-328
    • /
    • 2000
  • The solar wind contributes to the formation of unique space environment called the Earth's magnetosphere by various interactions with the Earth's magnetic field. Thus the solar-terrestrial environment affects the Earth's magnetic field, which can be observed with an instrument for the magnetic field measurement, the magnetometer usually mounted on the rocket and the satellite and based on the ground observatory. The magnetometer is a useful instrument for the spacecraft attitude control as well as the Earth's magnetic field measurements for the spacecraft purpose. In this paper, we present the preliminary design and test results of the two onboard magnetometers of KARI's (Korea Aerospace Research Institute) sounding rocket, KSR-3, which will be launched four times during the period of 2001-02. The KSR-3 magnetometers consist of the fluxgate magnetometer, MAG/AIM (Attitude Information Magnetometer) for acquiring the rocket flight attitude information, and of the search-coil magnetometer, MAG/SIM (Scientific Investigation Magnetometer) for the observation of the Earth's magnetic field fluctuations. With the MAG/AIM, the 3-axis attitude information can be acquired by the comparison of the resulting dc magnetic vector field with the IGRF (International Geomagnetic Reference Field). The Earth's magnetic field fluctuations ranging from 10 to 1,000 Hz can also be observed with the MAG/SIM measurement.

  • PDF

Residual magnetic field profiles and their current density profiles of coated conductors for fast and slow cut-off current operations

  • Sun, J.;Tallouli, M.;Shyshkin, O.;Hamabe, M.;Watanabe, H.;Chikumoto, N.;Yamaguchi, S.
    • 한국초전도ㆍ저온공학회논문지
    • /
    • 제17권1호
    • /
    • pp.17-20
    • /
    • 2015
  • Coated conductor is an important candidate for power cable applications due to its high current density. Even for DC power cable transmission, we must study the transport properties of HTS tapes after slow and fast discharge. In order to evaluate relation of the magnetic field with applied current we developed a scanning magnetic field measurements system by employing a Hall probe. This work presents the measurements of the magnetic fields above a coated conductor by varying applied current pattern. In the work, a transport current of 100 A, less than the critical current, is applied to YBCO coated conductor. We measured the residual magnetic field distributions after cut off the transport current with slow and fast operations. The results show differences of the magnetic field profiles and the corresponding current profiles by an inverse solution from the magnetic field measurement between these two operations because of the hysteresis of coated conductor excited by the transport current.