scholarly journals Eddy current measurement of the electrical conductivity and porosity of metal foams

2004 ◽  
Author(s):  
X. Ma ◽  
A.J. Peyton
Keyword(s):  
Electrical Conductivity ◽  
Eddy Current ◽  
Metal Foams ◽  
Current Measurement

Novel Noncontact Eddy Current Measurement of Electrical Conductivity

2018 ◽  
Vol 18 (22) ◽  
pp. 9352-9359 ◽  
Author(s):  
Cuiping Wang ◽  
Mengbao Fan ◽  
Binghua Cao ◽  
Bo Ye ◽  
Wei Li
Keyword(s):  
Electrical Conductivity ◽  
Eddy Current ◽  
Current Measurement

Analysis of Eddy-Current Measurement System for Residual Stress Assessment in Stainless Steel Grade 304

2015 ◽  
Vol 659 ◽  
pp. 623-627 ◽  
Author(s):  
Cherdpong Jomdecha ◽  
Isaratat Phung-On
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Eddy Current ◽  
Measurement System ◽  
System Analysis ◽  
Stress Measurement ◽  
Steel Grade ◽  
Current Measurement ◽  
Residual Stress Measurement ◽  
Stress Assessment

The objective of this paper is an analysis of statistical discreteness and measurement capability of an eddy-current measurement system for residual stress assessment in stainless steel Grade 304 (SS304). Cylindrical specimens with 50 mm in diameter and 12 mm thickness were prepared to generate residual stress by Resistance Spot Welding at which the welding currents were set at 12, 14, and 16 kA. The eddy-current measurement system was including a probe with frequency range of 0.1 to 3 MHz and an eddy current flaw detector. They were performed by contacting the probe on the specimen. The measurements were performed particularly in the vicinity of heat affected zone (HAZ). In order to determine the results of the residual stress measurement, the calibration curves between static tensile stress and eddy current impedance at various frequencies were accomplished. The Measurement System Analysis (MSA) was utilized to evaluate the changed eddy-current probe impedance from residual stress. The results showed that using eddy current technique at 1 MHz for residual stress measurement was the most efficient. It can be achieved the Gauge Repeatability & Reproducibility %GR&R at 16.61479 and Number of Distinct Categories (NDC) at 8. As applied on actual butt welded joint, it could yield the uncertainty of ± 58 MPa at 95 % (UISO).

Localization and Recognition of Different Vertebra Tissues Based on Eddy Current Detection Method

2013 ◽  
Vol 740 ◽  
pp. 128-133 ◽  
Author(s):  
Wei Wen Liu ◽  
Kai Jiang ◽  
Hui Zhao ◽  
Cheng Long Wang
Keyword(s):  
Electrical Conductivity ◽  
Internal Fixation ◽  
Eddy Current ◽  
Biological Tissue ◽  
Detection Method ◽  
Pedicle Screws ◽  
Human Beings ◽  
High Penetration ◽  
Trauma Injury ◽  
Current Detection

The spine, which is throughout the trunk, is of great importance to the skeleton structure of human beings. For spine is vulnerable, the rate of spine incident trauma injury is relatively high. In the contemporary technology, the internal fixation prosthetics with implanting pedicle screws is the most efficient way in clinical treatment. However spine internal fixation surgery has many disadvantages like complex in the operation, the high penetration rate and inability to be used in the field battle. As a result, according to the magnetic property difference of different vertebra tissues, an eddy current detection method which is used in localization and recognition of different vertebra tissues to realize the navigation of spine internal fixation surgery is proposed in this paper. A set of improved series-reverse-three coils eddy current sensor is used to test the NaCl solution which electrical conductivity matches that of biological tissue. And the result of several experiments indicates this method can detect the biological tissue with the electrical conductivity no less than 0.5 S/m, which lays a solid foundation to further study of recognition different vertebra tissues.

Eddy current measurement of the wall thickness and conductivity of circular non-magnetic conductive tubes

1996 ◽  
Vol 29 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Benoit de Halleux ◽  
Bruno de Limburg Stirum ◽  
Andrei I'tchelintsev
Keyword(s):  
Wall Thickness ◽  
Eddy Current ◽  
Current Measurement

scholarly journals Gas Diffusion Layers in Fuel Cells and Electrolysers: A Novel Semi-Empirical Model to Predict Electrical Conductivity of Sintered Metal Fibres

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 855 ◽  
Author(s):  
Reza Omrani ◽  
Bahman Shabani
Keyword(s):  
Electrical Conductivity ◽  
Fuel Cells ◽  
Gas Diffusion ◽  
Metal Foams ◽  
Critical Porosity ◽  
Gas Diffusion Layers ◽  
Open Cell ◽  
Diffusion Layers ◽  
Sintered Metal ◽  
Closed Cell

This paper introduces novel empirical as well as modified models to predict the electrical conductivity of sintered metal fibres and closed-cell foams. These models provide a significant improvement over the existing models and reduce the maximum relative error from as high as just over 30% down to about 10%. Also, it is shown that these models provide a noticeable improvement for closed-cell metal foams. However, the estimation of electrical conductivity of open-cell metal foams was improved marginally over previous models. Sintered porous metals are widely used in electrochemical devices such as water electrolysers, unitised regenerative fuel cells (URFCs) as gas diffusion layers (GDLs), and batteries. Having a more accurate prediction of electrical conductivity based on variation by porosity helps in better modelling of such devices and hence achieving improved designs. The models presented in this paper are fitted to the experimental results in order to highlight the difference between the conductivity of sintered metal fibres and metal foams. It is shown that the critical porosity (maximum achievable porosity) can play an important role in sintered metal fibres to predict the electrical conductivity whereas its effect is not significant in open-cell metal foams. Based on the models, the electrical conductivity reaches zero value at 95% porosity rather than 100% for sintered metal fibres.

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