High-Spatial Resolution Giant Magnetoresistive Sensors - Part I: Application in Non-Destructive Evaluation

Chomsuwan, Komkrit; Somsak, Teerasak; Gooneratne, Chinthaka P.; Yamada, S.

doi:10.1007/978-3-642-37172-1_9

Cited by 4 publications

(2 citation statements)

References 30 publications

(18 reference statements)

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“…Several solutions for ECT probes were presented in the literature [4][5][6][7][8], however the use of giant magnetoresistors (GMR) to replace the detection coils represents the current solution of higher sensitivity [9]. For instance, an ECT probe for high density printed circuit board (PCB) inspection was proposed and it was capable to detect defects whose dimensions were 70 μm (width) and 9 μm (thickness) on PCB tracks [10].…”

Section: Introductionmentioning

confidence: 99%

Design and analysis of a GMR eddy current probe for NDT

Porto

Brusamarello

Azambuja

et al. 2013

2013 Seventh International Conference on Sensing Technology (ICST)

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Defect detection in metallic plates represents an important issue in metal industry, because its potential use in quality control process. Eddy current testing is one of the most extensively used nondestructive techniques for inspecting electrically conductive materials. The purpose of this paper is to present an eddy current testing system for surface defect detection in conducting materials using a giant magnetoresistive (GMR) sensor. An alternate magnetic field is produced by a solenoid and eddy currents are generated in the material under test. The GMR sensor was mounted inside the coil and the arrangement was adapted in the axis of a vertical machining center. In order to validating the measurement device, defects were induced by cracks machined in workpieces made of aluminum. Thus, the parts were scanned with the sensor prototype and a method to estimate the width and depth of the induced defects was proposed after analyzing the output voltage signal.

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Section: Introductionmentioning

confidence: 99%

Design and analysis of a GMR eddy current probe for NDT

Porto

Brusamarello

Azambuja

et al. 2013

2013 Seventh International Conference on Sensing Technology (ICST)

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“…The detection of deep, embedded cracks in multilayer riveted structures [ 1 , 2 , 3 , 4 ] is a major challenge in eddy-current (EC) non-destructive testing (NDT). Ultra-low frequency excitation along with giant magnetoresistive (GMR) sensor [ 5 ] to measure the induced magnetic field directly (EC-GMR) have been used to increase penetration depth as well as guarantee a good signal to noise ratio [ 6 , 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Optimization and Validation of Rotating Current Excitation with GMR Array Sensors for Riveted Structures Inspection

Удпа

2016

Sensors

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In eddy current non-destructive testing of a multi-layered riveted structure, rotating current excitation, generated by orthogonal coils, is advantageous in providing sensitivity to defects of all orientations. However, when used with linear array sensors, the exciting magnetic flux density (Bx) of the orthogonal coils is not uniform over the sensor region, resulting in an output signal magnitude that depends on the relative location of the defect to the sensor array. In this paper, the rotating excitation coil is optimized to achieve a uniform Bx field in the sensor array area and minimize the probe size. The current density distribution of the coil is optimized using the polynomial approximation method. A non-uniform coil design is derived from the optimized current density distribution. Simulation results, using both an optimized coil and a conventional coil, are generated using the finite element method (FEM) model. The signal magnitude for an optimized coil is seen to be more robust with respect to offset of defects from the coil center. A novel multilayer coil structure, fabricated on a multi-layer printed circuit board, is used to build the optimized coil. A prototype probe with the optimized coil and 32 giant magnetoresistive (GMR) sensors is built and tested on a two-layer riveted aluminum sample. Experimental results show that the optimized probe has better defect detection capability compared with a conventional non-optimized coil.

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