Multi-Frequency Magnetic Induction Tomography System and Algorithm for Imaging Metallic Objects

Abstract

Magnetic induction tomography (MIT) is largely focused on applications in biomedical and industrial process engineering. MIT has a great potential for imaging metallic samples; however, there are fewer developments directed toward the testing and monitoring of metal components. Eddy-current non-destructive testing is well established, showing that corrosion, fatigue and mechanical loading are detectable in metals. Applying the same principles to MIT would provide a useful imaging tool for determining the condition of metal components. A compact MIT instrument is described, including the design aspects and system performance characterisation, assessing dynamic range and signal quality. The image rendering ability is assessed using both external and internal object inclusions. A multi-frequency MIT system has similar capabilities as transient based pulsed eddy current instruments. The forward model for frequency swap multi-frequency is solved, using a computationally efficient numerical modelling with the edge-based finite elements method. The image reconstruction for spectral imaging is done by adaptation of a spectrally correlative base algorithm, providing whole spectrum data for the conductivity or permeability.

Electrical Resistance Tomographic by Using Current Injection and Magnetic Field Induction

“…The Tikhonov regularization (Dingley and Soleimani, 2021) is used to get a solution so that equation ( 8) turns into equation ( 9). ∆𝜌̅ = (𝑆 + 𝛼𝐼) −1 ∆𝑉 ̅ (9) And finally, resistivity reconstruction results were obtained through 𝜌 𝑎𝑛𝑜𝑚𝑎𝑙𝑖 = 𝜌 ℎ𝑜𝑚𝑜𝑔𝑒𝑛 + ∆𝜌̅ (10) Reconstruction results are evaluated numerically using the parameters of root mean square (RMS) as equation ( 11), and it's called Error.…”

Experimental Characterization Techniques for Solid-Liquid Slurry Flows in Pipelines: A Review

“…EMT does not require direct contact with the medium being examined, which is one of its several advantages, making it particularly useful for industrial environments, since in some applications the placing of contact electrodes is cumbersome, if not impossible. Another advantage is the possibility to characterize fully metallic materials or mediums, i.e., with a very high conductivity; in ECT and EIT, the trans-impedances and permittivities, respectively, would be very small indeed and difficult to be measured [97][98][99].…”

Design of soft-magnetic shield in electromagnetic tomography

“…It has been applied in industry (e.g. the monitoring of the melting process [1,2], the testing of metal/non-metal components [3][4][5], and the visualization of the multiphase flow processes in fluidized beds [6][7][8][9]) and in biomedicine [10][11][12][13].…”