scholarly journals GMR Sensor Utilization for PCB Inspection Based on the Eddy-Current Testing Technique

2004 ◽  
Vol 4 (1) ◽  
pp. 39-42 ◽  
Author(s):  
K. Chomsuwan ◽  
Y. Fukuda ◽  
S. Yamada ◽  
M. Iwahara ◽  
H. Wakiwaka ◽  
...  
2005 ◽  
Vol 41 (10) ◽  
pp. 3622-3624 ◽  
Author(s):  
S. Yamada ◽  
K. Chomsuwan ◽  
T. Hagino ◽  
H. Tian ◽  
K. Minamide ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 419
Author(s):  
Xiaobai Meng ◽  
Mingyang Lu ◽  
Wuliang Yin ◽  
Abdeldjalil Bennecer ◽  
Katherine J. Kirk

Defect detection in ferromagnetic substrates is often hampered by nonmagnetic coating thickness variation when using conventional eddy current testing technique. The lift-off distance between the sample and the sensor is one of the main obstacles for the thickness measurement of nonmagnetic coatings on ferromagnetic substrates when using the eddy current testing technique. Based on the eddy current thin-skin effect and the lift-off insensitive inductance (LII), a simplified iterative algorithm is proposed for reducing the lift-off variation effect using a multifrequency sensor. Compared to the previous techniques on compensating the lift-off error (e.g., the lift-off point of intersection) while retrieving the thickness, the simplified inductance algorithms avoid the computation burden of integration, which are used as embedded algorithms for the online retrieval of lift-offs via each frequency channel. The LII is determined by the dimension and geometry of the sensor, thus eliminating the need for empirical calibration. The method is validated by means of experimental measurements of the inductance of coatings with different materials and thicknesses on ferrous substrates (dual-phase alloy). The error of the calculated coating thickness has been controlled to within 3% for an extended lift-off range of up to 10 mm.


2019 ◽  
Vol 68 (5) ◽  
pp. 1533-1542 ◽  
Author(s):  
Andrea Bernieri ◽  
Luigi Ferrigno ◽  
Marco Laracca ◽  
Antonio Rasile

2014 ◽  
Vol 11 (4) ◽  
pp. 535-549 ◽  
Author(s):  
Hartmut Brauer ◽  
Marek Ziolkowski ◽  
Hannes Toepfer

Lorentz force eddy current testing (LET) is a novel nondestructive testing technique which can be applied preferably to the identification of internal defects in nonmagnetic moving conductors. The LET is compared (similar testing conditions) with the classical eddy current testing (ECT). Numerical FEM simulations have been performed to analyze the measurements as well as the identification of internal defects in nonmagnetic conductors. The results are compared with measurements to test the feasibility of defect identification. Finally, the use of LET measurements to estimate of the electrical conductors under test are described as well.


Author(s):  
Xiaobai Meng ◽  
Mingyang Lu ◽  
Wuliang Yin ◽  
Abdeldjalil Bennecer ◽  
Katherine Kirk

Defect detection in ferromagnetic substrates is often hampered by non-magnetic coating thickness variation when using conventional eddy current testing technique. The lift-off distance between the sample and the sensor is one of the main obstacles for the thickness measurement of non-magnetic coatings on ferromagnetic substrates when using the eddy current testing technique. Based on the eddy current thin-skin effect and the lift-off insensitive inductance (LII), a simplified iterative algorithm is proposed for reducing the lift-off variation effect using a multi-frequency sensor. Compared to the previous techniques on compensating the lift-off error (e.g., the lift-off point of intersection) while retrieving the thickness, the simplified inductance algorithms avoid the computation burden of integration, which are used as embedded algorithms for the online retrieval of lift-offs via each frequency channel. The LII is determined by the dimension and geometry of the sensor, thus eliminating the need for empirical calibration. The method is validated by means of experimental measurements of the inductance of coatings with different materials and thicknesses on ferrous substrates (dual-phase alloy). The error of the calculated coating thickness has been controlled to within 3 % for an extended lift-off range of up to 10 mm.


2018 ◽  
Vol 225 ◽  
pp. 02021 ◽  
Author(s):  
Moneer A Faraj ◽  
Ahmed N Abdalla ◽  
Fahmi Bin Samsuri ◽  
Damhuji Rifai ◽  
Kharudin Ali

Eddy current testing is a widely applied non-destructive technique in different sections of industries. Nowadays eddy current testing is an accurate, widely used and well-understood inspection technique, particularly in the aircraft and nuclear industries. The main purpose of this paper is to construct an eddy current probe by using transmission coil and using a Giant Magneto resistance (GMR) sensor for detection medium. This probe only use a magnetic field to operational in detection of flaws. A transmission coil is an object made from a material that is magnetized and creates its own persistent magnetic field. A GMR-coil probe has been used to inspect two different material of calibration block. Experimental results obtained by scanning A GMR-coil probe over Brass calibration block has 10 slots with different depth from 0.5mm to 5mm and mild steel has 8 slots with different depth from 0.5mm to 4mm are presented. The result prove that GMR-coil probe that operated using a magnetic field and sensor more effective on ferromagnetic material.


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