Eddy Current Testing (ET)

Eddy Current Testing (ET) is a versatile NDT method that can be used to detect (near) surface defects in conductive materials without removing the coating. An electromagnetic inductor is used to generate a magnetic field. When this field is introduced in the surface of the test piece, it generates so called "eddy currents" in the material. These currents generate their own magnetic field which resists the initial field created by the inductor. When a discontinuity disturbs the eddy currents, this can be registered by measuring the resulting change in impedance of the coil. 

Besides detecting defects in the (near) surface, ET inspections can also be applied for material and coating thickness measurements, material identification and heat treatment monitoring. 

Contact us if you have a question or want to receive a quotation!


ET Advantages:

  • No need to remove coating

  • Can be used to detect small cracks and other defects

  • Suitable for detecting surface and near surface defects

  • Immediate results on screen

  • Portable inspection equipment

  • Also suitable for coating thickness measurements, material identification and heat treatment monitoring

  • No significant surface preparation required

  • No need for couplant liquid or gel

  • Can be used to inspect objects with complex geometry

ET Limitations:

  • Can only be applied on conductive materials

  • Higher skill and training level required than with other techniques

  • Surface finish and roughness can cause false indications

  • Reference standards required for setup of the system

  • Limited depth penetration

  • Discontinuities that lie parallel to the probe coil winding and probe scan direction are undetectable

Henk Schroots

Area Sales Manager NDT & Laboratory
+31 (0) 6 49 35 78 02

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