The influence of magnetic head’s pose on magnetic flux leakage detection

2020 ◽  
Vol 64 (1-4) ◽  
pp. 493-500
Author(s):  
Jian Tang ◽  
Rongbiao Wang ◽  
Jikai Zhang ◽  
Yihua Kang
Keyword(s):  
Magnetic Field ◽  
Tilt Angle ◽  
High Sensitivity ◽  
Vertical Axis ◽  
Magnetic Core ◽  
Iron Core ◽  
Destructive Testing ◽  
Practical Applications ◽  
Leakage Magnetic Field ◽  
Leakage Field

As a high-sensitivity magnetic sensor, the magnetic head has been gradually applied to non-destructive testing. Compared with the single coil and the coil with an iron core, the magnetic core can converge the weak leakage magnetic field because it can form a magnetic circuit to transmit the leakage field to the coil wound thereon. So that it has a higher sensitivity. However, in practical applications, it’s found that the pose error of the head affects its sensitivity. Therefore, this paper analyzes the influence of the tilt of the head on the magnetic core’s ability to sense leakage magnetic field, and then the influence is verified by simulations and experiments. The study finds that, when tilted around two horizontal axes, the larger the tilt angle is, the larger the signal is. When tilted around the vertical axis, the larger the tilt angle is, the smaller the signal is.

Finite Element Analysis and Research on Corrosion Defect of Tank Floor

2016 ◽  
Vol 853 ◽  
pp. 514-518
Author(s):  
Zhi Jun Yang ◽  
De Shu Chen ◽  
Liang Chen ◽  
Yu Zhuo Liu ◽  
Ran An ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Bottom Plate ◽  
Element Analysis ◽  
Corrosion Defect ◽  
Leakage Magnetic Field ◽  
Leakage Field ◽  
Flux Leakage

Storage tank is an essential vessel in petrochemical industry, and the corrosion of tank is an important reason for the safety hazard. The corrosion of tank bottom plate is more serious than the tank wall, and it is not easy to check and repair, when damaged to a certain extent it will cause the leakage of the media, then lead to waste of energy, environmental pollution, at the same time it will cause a major accident. Magnetic flux leakage testing is widely used in the field of tank floor inspection with the advantages of fast scanning speed, accurate results and so on. In this paper, the finite element simulation and analysis of the corrosion defect leakage magnetic field is used to obtain the data, and the characteristic of the leakage magnetic field is extracted. The effect of defect depth and width and shape on the magnetic flux leakage field is studied, and the distribution curve of the magnetic flux leakage field is obtained.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

Digital phase analysis in interference electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 842-843
Author(s):  
S. Hasegawa ◽  
T. Kawasaki ◽  
J. Endo ◽  
M. Futamoto ◽  
A. Tonomura
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Phase Distribution ◽  
Magnetic Recording Media ◽  
Electron Wave ◽  
Vector Potentials ◽  
Weak Magnetic Fields ◽  
Leakage Magnetic Field ◽  
Optical Reconstruction ◽  
Processing Techniques

Interference electron microscopy enables us to record the phase distribution of an electron wave on a hologram. The distribution is visualized as a fringe pattern in a micrograph by optical reconstruction. The phase is affected by electromagnetic potentials; scalar and vector potentials. Therefore, the electric and magnetic field can be reduced from the recorded phase. This study analyzes a leakage magnetic field from CoCr perpendicular magnetic recording media. Since one contour fringe interval corresponds to a magnetic flux of Φo(=h/e=4x10-15Wb), we can quantitatively measure the field by counting the number of finges. Moreover, by using phase-difference amplification techniques, the sensitivity for magnetic field detection can be improved by a factor of 30, which allows the drawing of a Φo/30 fringe. This sensitivity, however, is insufficient for quantitative analysis of very weak magnetic fields such as high-density magnetic recordings. For this reason we have adopted “fringe scanning interferometry” using digital image processing techniques at the optical reconstruction stage. This method enables us to obtain subfringe information recorded in the interference pattern.

Dual magnetic field and temperature optical probes of controlled crystalline phases in lanthanide doped multi-shell nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Flavia de Sousa Ferreira ◽  
Amanda Justino de Morais ◽  
Claudia Manuela Santos Calado ◽  
Gabriel Brunet ◽  
Fernando Iikawa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Core ◽  
Optical Probes ◽  
Shell Nanoparticles ◽  
Crystalline Phases

The engineering of core@multi-shell nanoparticles containing heterogeneous crystalline phases in different layers constitutes an important strategy for obtaining optical probes. The possibility of obtaining an opto-magnetic core@multi-shell nanoparticle capable of...

High-sensitivity fiber optic magnetic field sensor based on lossy mode resonance and hollow core-offset structure

2021 ◽  
pp. 1-12
Author(s):  
Xue-Peng Jin ◽  
Hong-Zhi Sun ◽  
Shuo-Wei Jin ◽  
Wan-Ming Zhao ◽  
Jing-Ren Tang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fiber Optic ◽  
High Sensitivity ◽  
Magnetic Field Sensor ◽  
Hollow Core ◽  
Field Sensor

scholarly journals Alcohol-based highly conductive polymer for conformal nanocoatings on hydrophobic surfaces toward a highly sensitive and stable pressure sensor

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jung Joon Lee ◽  
Srinivas Gandla ◽  
Byeongjae Lim ◽  
Sunju Kang ◽  
Sunyoung Kim ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Mechanical Stability ◽  
Exchange Process ◽  
Conductive Polymer ◽  
High Sensitivity ◽  
Fast Response ◽  
Pdms Surface ◽  
Practical Applications ◽  
Sensor Applications ◽  
Water Based

Abstract Conformal and ultrathin coating of highly conductive PEDOT:PSS on hydrophobic uneven surfaces is essential for resistive-based pressure sensor applications. For this purpose, a water-based poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) solution was successfully exchanged to an organic solvent-based PEDOT:PSS solution without any aggregation or reduction in conductivity using the ultrafiltration method. Among various solvents, the ethanol (EtOH) solvent-exchanged PEDOT:PSS solution exhibited a contact angle of 34.67°, which is much lower than the value of 96.94° for the water-based PEDOT:PSS solution. The optimized EtOH-based PEDOT:PSS solution exhibited conformal and uniform coating, with ultrathin nanocoated films obtained on a hydrophobic pyramid polydimethylsiloxane (PDMS) surface. The fabricated pressure sensor showed high performances, such as high sensitivity (−21 kPa−1 in the low pressure regime up to 100 Pa), mechanical stability (over 10,000 cycles without any failure or cracks) and a fast response time (90 ms). Finally, the proposed pressure sensor was successfully demonstrated as a human blood pulse rate sensor and a spatial pressure sensor array for practical applications. The solvent exchange process using ultrafiltration for these applications can be utilized as a universal technique for improving the coating property (wettability) of conducting polymers as well as various other materials.

scholarly journals Shock Pulse Shaping in a Small-Form Factor Velocity Amplifier

2010 ◽  
Vol 17 (6) ◽  
pp. 787-802 ◽  
Author(s):  
Gerard Kelly ◽  
Jeff Punch ◽  
Suresh Goyal ◽  
Michael Sheehy
Keyword(s):  
Pulse Shaping ◽  
Vertical Axis ◽  
Mechanical Shock ◽  
Practical Applications ◽  
Shock Testing ◽  
Acceleration Signal ◽  
High Acceleration ◽  
Component Assembly ◽  
Small Form Factor ◽  
Shock Pulses

This theme of this paper is the design and characterisation of a velocity amplifier (VAMP) machine for high-acceleration shock testing of micro-scale devices. The VAMP applies multiple sequential impacts to amplify velocity through a system of three progressively smaller masses constrained to move in the vertical axis. Repeatable, controlled, mechanical shock pulses are created through the metal-on-metal impact between pulse shaping test rods, which form part of the penultimate and ultimate masses. The objectives are to investigate the controllable parameters that affect the shock pulses induced on collision, namely; striker and incident test rod material; test rod length; pulse shaping mechanisms; and impact velocity. The optimum VAMP configuration was established as a 60 mm long titanium striker test rod and a 120 mm long titanium incident rod. This configuration exhibited an acceleration magnitude and a primary pulse duration range of 5,800–23,400 g and 28.0–44.0μs respectively. It was illustrated that the acceleration spectral content can be manipulated through control of the test rod material and length. This is critical in the context of practical applications, where it is postulated that the acceleration signal can be controlled to effectively excite specific components in a multi-component assembly affixed to the VAMP incident test rod.

Sign in / Sign up

Export Citation Format

Share Document