What it is and how we do it at Technomix

Eddy-current testing

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Thomas Kraus

Senior executive

Eddy-current testing in a nutshell

  • Eddy-current testing is a quality-assurance procedure used for electrically conductive materials to ascertain whether the material properties are correct and whether a part or component has been finished uniformly and undamaged both internally and externally.
  • It is a non-destructive material test (NDT). Its main advantage is its high level of sensitivity and testing speed, even when compared with classic visual inspection (although it must be emphasised here that the inspection characteristics of visual inspection and eddy-current testing only partly overlap).
  • Eddy-current testing basically involves the application of an electrical current to induce an alternating magnetic field in and around the test piece without magnetising the test piece itself. Cracks, discontinuities or other abnormalities cause a change in the alternating current, and therefore in the magnetic field, thus allowing rapid assessments to be made about the properties and internal condition of the test piece.
  • Eddy-current testing is contactless and quick and can also be used for test pieces that have a complex construction. In addition, the frequency of the alternating current can be altered to penetrate the material more deeply.
  • Technomix offers eddy-current testing with maximum levels of precision, including with semi-automatic ibg eddyvisor S testing devices and a test cycle of around one part per second.

Ensure that the internal quality of your materials matches its specifications.

Through the crust and into the test piece’s mantle and core: No other non-destructive testing method allows the internal condition of a test specimen to be inspected so quickly. Microscopic cracks, pores, grinding burns and other irregularities both close to or on the surface, and inside the test piece, can be detected immediately.

At the same time, the test provides specific information about whether the thickness, hardness, and structure, as well as the strength, heat treatment and alloying of the material and its individual layers meet the specifications.

Request your non-binding quotation today.

Trust in our company’s high quality standards and straightforward processes and find out how eddy-current testing and other material tests can make complaints and their associated contract risks a thing of the past.

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How does eddy-current testing work?

In short, with a voltage source and an electric coil. The voltage source generates an alternating current. This creates an alternating magnetic field around the coil. If an intact, conductive object is then passed through the coil, this induces an eddy current on the object, which generates a second, equal alternating magnetic field, always opposite to the magnetic field of the coil.

The trick to eddy-current testing is that the magnetic field of the eddy current changes when damage, imperfections, and changes in material properties such as hardness or permeability interrupt the even flow of current. If there are cracks, for example, the eddy currents look for a way around the crack. This immediately becomes apparent and indicates that there is a flaw in the material. In the case of alloys, the same thing happens if the metal compounds are imbalanced.

In tests, these types of changes and their intensity are crucial when it comes to judging whether the material is free from defects and whether it matches its material specifications. Manufacturing companies can thus use eddy-current testing to ensure that their products are in a flawless condition.

Technomix can also arrange for the reshipment of intact parts to the end customer after eddy-current testing. This means we are the final quality assurance step between production and further processing on the customer’s side. (This is also referred to as screening inspection.)

Still unsure about the benefits of eddy-current testing?

A complex electromagnetic procedure for clear and precise results: Technomix is regularly enlisted by companies, predominantly from the automobile and aerospace industries, that want to ensure that their customers receive only flawless products. Eddy-current testing is just part of our extensive range of services. Tell us what you require today and become one of the many satisfied customers who trust in the extraordinary levels of precision and reliable appraisals of our highly qualified inspection personnel.

Free, non-binding offers with quick response times.

Thomas Kraus

Senior executive

Service & Logistik


Service & logistics


Designing inspection machines