Giant Magnetoresistance Sensors: A Review on Structures and Non-Destructive Eddy Current Testing Applications

The first publications describing the physical principles of the non-destructive remote field eddy current testing method appeared about 30 years ago. This method allows to significantly expand the field of application of eddy current testing. However, due to the lack of a theoretical justification, this method did not get widespread use around the world. Domestic publications in this area are completely absent, and the descriptions given in few foreign publications often contradict each other. There are no results of full-scale simulation using numerical methods in available domestic and foreign sources. The distinctive feature of this method under consideration is the ability of detecting defects on the external (with respect to the eddy current transducer) side of the tested object, which is impossible for the classical eddy current method due to the limited eddy current penetration depth. The basics of the method were considered, the distinctive features were presented, and the advantages and disadvantages of remote field eddy current testing of metals were pointed out. A numerical simulation with the subsequent analysis of the obtained results has been carried out, the transducer design for remote field eddy current testing is given. The influence of various factors on the change in the added voltage of the signal coil of the eddy current transducer in the presence of a defect in the external wall of the tube was considered. Expressions that determine the optimal ratio of the diameters of the transducer and the tested product were obtained. The values of the test parameters and the limiting wall thickness of the tested ferromagnetic product were determined.

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Advanced procedure for non-destructive diagnosis of real cracks from eddy current testing signals

2014 ELEKTRO ◽

10.1109/elektro.2014.6848961 ◽

2014 ◽

Author(s):

Ladislav Janousek ◽

Milan Smetana ◽

Tatiana Strapacova ◽

Mihai Rebican ◽

Anton Duca

Keyword(s):

Eddy Current ◽

Eddy Current Testing ◽

Current Testing ◽

Non Destructive

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Numerical simulation of non-destructive remote field eddy current testing of rolled metal tubes

Journal of Physics Conference Series ◽

10.1088/1742-6596/1327/1/012012 ◽

2019 ◽

Vol 1327 ◽

pp. 012012

Author(s):

A G Efimov ◽

B M Kanter ◽

N R Kuzelev ◽

E V Martyanov ◽

A E Shubochkin

Keyword(s):

Numerical Simulation ◽

Eddy Current ◽

Eddy Current Testing ◽

Rolled Metal ◽

Current Testing ◽

Non Destructive

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Physic perspective fusion of electromagnetic acoustic transducer and pulsed eddy current testing in non-destructive testing system

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2019.0608 ◽

2020 ◽

Vol 378 (2182) ◽

pp. 20190608

Author(s):

Wei Guo ◽

Bin Gao ◽

Gui Yun Tian ◽

Dan Si

Keyword(s):

Eddy Current ◽

Surface Defects ◽

Eddy Current Testing ◽

Non Destructive Testing ◽

Electromagnetic Acoustic Transducer ◽

Destructive Testing ◽

Current Testing ◽

Pulsed Eddy Current ◽

Acoustic Transducer ◽

Non Destructive

Comprehensive non-destructive testing (NDT) for pipelines is a critical and challenging task. This paper proposes a novel physic perspective fusion NDT method of electromagnetic acoustic transducer (EMAT) and pulsed Eddy current testing (PECT) for detecting hybrid defects. This transceiver-integrated fusion sensor structure can simultaneously excite ultrasound and pulsed eddy current. Therefore, the generated ultrasound is applied to detect deep defects, while the eddy current detects surface defects. The theoretical derivation of EMAT and PECT fusion mechanism has been developed for analysis and interpretation of the results. In addition, numerical simulation on the detection of hybrid defects including surface defects with different width, depth and multiple bottom-thinning defects has been conducted. Experiments on both ferromagnetic and non-ferromagnetic material verify the feasibility of composite detection. Finally, tests have been validated on pipeline with weld defects, and the results show that the composite inspection method is capable of monitoring thickness variations and inspecting surface defects. This article is part of the theme issue ‘Advanced electromagnetic non-destructive evaluation and smart monitoring’.

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Construct Coil Probe Using GMR Sensor for Eddy Current Testing

MATEC Web of Conferences ◽

10.1051/matecconf/201822502021 ◽

2018 ◽

Vol 225 ◽

pp. 02021 ◽

Cited By ~ 1

Author(s):

Moneer A Faraj ◽

Ahmed N Abdalla ◽

Fahmi Bin Samsuri ◽

Damhuji Rifai ◽

Kharudin Ali

Keyword(s):

Magnetic Field ◽

Eddy Current ◽

Ferromagnetic Material ◽

Eddy Current Testing ◽

Current Testing ◽

Calibration Block ◽

Gmr Sensor ◽

Non Destructive ◽

Magneto Resistance ◽

Detection Medium

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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