Recycling automotive, electronic, and other end-of-life waste liberates large quantities of metals, which can be returned to the supply chain. Sorting the nonferrous metals, however, is not straightforward.

The frequency response of electromagnetic (EM) sensors is closely related to the electromagnetic properties(conductivity and permeability) of the metals:

The magnetic field induced in an object, in response to different frequency excitation magnetic fields.

This induces eddy-currents to circulate in the object, which in turn induces a secondary or scattered magnetic field

Therefore, EM methods can identify and sort nonferrous scrap efficiently and economically.

Walk-through metal detection (WTMD) has proven to be a fundamental part of the screening of large numbers of personnel for potential threat objects and WTMD use is widespread in locations such as airports, prisons, embassies, ports and government buildings.

It is required to detect prohibited metallic items such as knives, guns and components of explosive devices out of a secured area.

EM methods typically rely upon the heuristic analysis of peak signal responses from an array of coils, and relating these to their approximate locations.

Carbon fibre reinforced polymer(CFRP) is an extremely strong and light fiber-reinforced plastic which contains carbon fibers. CFRPs are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications.

Structural health monitoring (SHM) of the CFRP, such as missing carbonfibre bundles, lanes, suspensions, fringes, missing sewing threads, angle errors and hidden manufacturing defects, is an invaluable quality control.

EM testing can be applied to monitor the structural health and detect defects of CFRP due to its contact-less, noninvasive nature.

In fluid mechanics, multiphase flow is the simultaneous flow of materials with two or more thermodynamic phases.

Multi-phase flow imaging is a challenging topic in industrial process tomography.

Magnetic induction tomography (MIT) is sensitive to the conductivity of the target, and as such has the potential to be used as an imaging technique to visualise the conductive components in a multi-phase flow application.

Eddy current analysis could provide an indication of conductivity change within a biological body. EM testing is noninvasive and contactless technology and especially attractive for possible biomedical applications, for example intracranial hematoma monitoring and brain tumor detecting.

Ensuring the highest product quality and safety for brand and end user protection is very important in food industries. Final inspection of products at the end of the production line is the last line of defense to detect any foreign bodies before shipping to retailers and supermarkets.

EM methods are capable of detecting the physical contamination due to the different conductivity between the food and the foreign bodies.

Eddy-current testing is one of many electromagnetic testing methods used in nondestructive testing (NDT) making use of electromagnetic induction to detect and characterize surface and sub-surface flaws in conductive materials.

Excitation coil produces an alternating magnetic field around itself. When the coil approaches a conductive material, currents opposite to the ones in the coil are induced in the material — eddy currents.

Variations in the electrical conductivity and magnetic permeability of the test object, and the presence of defects causes a change in eddy current and a corresponding change in phase and amplitude that can be detected by measuring the impedance changes in the coil, which is a telltale sign of the presence of defects.

ECT has a very wide range of applications in the aerospace industry and in other manufacturing and service environments that require inspection of thin metal for potential safety-related or quality-related problems.

Anti-personnel mines remain a global challenge with contaminated land estimated to be 300 𝒌𝒎^𝟐 world-wide.

The main challenge for landmine detectors has shifted over the last decade towards the classification of metallic content as opposed to detection.

Typical electromagnetic induction (EMI) sensors are composed of an excitation coil which generates a primary magnetic field and a receive coil used to measure the induced fields caused by interactions with surrounding material. Eddy currents generated in the metallic target as a result of the time-varying primary field are dependent on a number of parameters such as size, shape, material and location.

In the manufacturing of steel strip for the automotive sector, the mechanical properties are largely defined by the process conditions in the hot strip mill. In particular the phase transformation, from austenite to ferrite, which takes place during the forced cooling stages on the run out table (ROT) after the finishing mill, governs the microstructure and hence the mechanical properties.

At present, there is no direct method for monitoring the steel microstructure transformation online; However, the EM method is an attempt to make direct measurement of the micro- structure, and has particular virtues, for instance, being non-contact, having a fast response, being unaffected by water and dust, and having low cost.