Untitled

Auld, B. A.; Moulder, John C.

doi:10.1023/a:1021898520626

Cited by 268 publications

(46 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Traditionally, this is achieved by monitoring the impedance of the rf coil (or a dedicated pickup coil). [1][2][3][4][5] However, the simplicity of instrumentation in this type of measurement is outweighed by the signal sensitivity degradation at low frequencies. Alternatives involve the implementation of magnetic sensors such as giant magnetoresistance (GMR) magnetometers, [6][7][8] superconducting quantum interference devices (SQUIDs), 9,10 and radio-frequency magnetometers.…”

Section: Introductionmentioning

confidence: 99%

Enhanced material defect imaging with a radio-frequency atomic magnetometer

Bevington

Gartman

Chałupczak

2019

Journal of Applied Physics

View full text Add to dashboard Cite

Imaging of structural defects in a material can be realized with a radio-frequency atomic magnetometer by monitoring the material's response to a radio-frequency excitation field. We demonstrate two measurement configurations that enable the increase of the amplitude and phase contrast in images that represent a structural defect in electrically conductive and magnetically permeable samples. Both concepts involve the elimination of the excitation field component, orthogonal to the sample surface, from the atomic magnetometer signal. The first method relies on the implementation of a set of coils that directly compensates the excitation field component in the magnetometer signal. The second takes advantage of the fact that the radio-frequency magnetometer is not sensitive to the magnetic field oscillating along one of its axes. Results from simple modelling confirm the experimental observation and are discussed in detail. Published under license by AIP Publishing. https://doi.Published under license by AIP Publishing.FIG. 3. The modelled change in the signal phase (dotted black line) and the amplitude (solid red line) of the magnetic resonance signal over a recess recorded by a magnetometer for various amplitudes of the primary field components. The vertical axis of the image array represents changes in the vertical component, while the horizontal axis represents changes in the horizontal component of the primary field. Amplitude is expressed in units of b y,max .Journal of Applied Physics ARTICLE scitation.org/journal/jap

show abstract

Section: Introductionmentioning

confidence: 99%

Enhanced material defect imaging with a radio-frequency atomic magnetometer

Bevington

Gartman

Chałupczak

2019

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…This difference in impedance ∆Z = Z b − Z a can be calculated by integration over a surface enclosing the defect (see Auld and Moulder [7]). With the index b denoting the case in presence of a defect and a the case in absence of a defect ∆Z can be calculated as…”

Section: Numerical Calculationsmentioning

confidence: 99%

The transition matrix method for a 2D eddy current interaction problem

Larsson¹,

Rosell²

2012

AIP Conference Proceedings

View full text Add to dashboard Cite

ABSTRACT. A 2D model of the eddy current interaction problem that consists of an inhomogeneity in a conductive half space is presented. The applied analytical method of solution is the transition (T) matrix method. This involves use of the free space Green's function to generate a system of boundary integral relations. In this way, it is easy to identify the contributions to the total solution from each different scattering surface. The different parts are separated also in the computation of the impedance. This leads to low cost simulations in terms of computation time and qualify the method to be used to obtain probability of detection (POD) curves. The T matrix method is a building block method and the possibility to extend the geometry with several inhomogeneities and extra layers will be discussed. The model is compared with a Finite Element (FE) model and numerical examples for the case with a cylindrical inhomogeneity are given.

show abstract

“…Advantage of the eddy current testing is that it is noncontact, high speedy, automatic implementable, excellent to surface detection, tolerant to high temperature and pressure. On the other hand, its disadvantage is that it is difficult to inspect internal state of thick material and is not applicable to ferromagnetic metals [1], [2]. Several researchers have examined the EC techniques for metallurgical characterization of different alloys [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Scanning the steel 08G2B using superminiature eddy current probe

et al. 2020

View full text Add to dashboard Cite

The article describes a hardware and software complex designed for defectoscopy and study of material properties. Sections of high-strength steel 08G2B pipes were scanned in the course of the research. The purpose of this study is to determine dependency of eddy current sensor signal and mechanical and operational properties of the base metal (K65 steel grade) and demonstrate the ability of developed eddy current probe to detect continuity defects and corrosion in this type of metal. The steel is ultra-low-carbon, which makes it possible to study their properties using the eddy current method. The eddy current method is a non-contact one being used both for cracks identification and determination of their characteristics. A special superminiature eddy current probe was developed, which includes three coils - stabilizing, measuring and exciting. The coils were placed on a pyramid-shaped core made of alloy 81NMA. The eddy-current transducer runs under the control of the developed hardware-software complex with a system for suppression of noise and amplification of signal received from the eddycurrent transducer. Signal processing makes it possible to separate the effects of closely spaced cracks on the eddy-current transducer signal and evaluate the contribution of each crack separately. As a parameter containing information about the presence of defects in the object of control, the voltage arrived at the measuring coil of the eddy current probe signal was used. The work studied sections of pipes with model continuity defects – cracks and holes. A research that allows to simulate the presence of corrosion in the metal was also conducted. The extreme values of the eddy current probe signal over defects of different types are obtained at various velocity, that allows to identify the type of defect, while changing the frequency of the signal on the probe allows to determine the depth of the defect.

show abstract

Untitled

Cited by 268 publications

References 34 publications

Enhanced material defect imaging with a radio-frequency atomic magnetometer

Enhanced material defect imaging with a radio-frequency atomic magnetometer

The transition matrix method for a 2D eddy current interaction problem

Scanning the steel 08G2B using superminiature eddy current probe

Contact Info

Product

Resources

About