prEN 18328

Non-destructive testing - Thermographic testing - Active thermography with inductive excitation

Publication date:   Mar 19, 2026

Scope

This document specifies a method and establishes guidelines for non-destructive testing using active thermography with inductive excitation.
By using inductive heating of the test object, this active thermography method is suitable for inspecting test objects made of metals or other electrically conductive materials.
Such tests are conducted for:
- the detection of surface-breaking discontinuities, particularly cracks; and
- the detection of discontinuities located near the surface.
The functional principle of the defect detection can be based on a direct interaction of defect and excitation signal (defect selective) or an indirect interaction by using derivations of the applied heat flow.
For this purpose, active thermography with inductive excitation is conducted using different sources of excitation (inductors) in reflection and transmission configurations. Areas tested in one shot are typically between a few cm2 and a few hundred cm2, depending on the geometry of the used inductor. In dynamic configuration, larger areas can be tested.
Fields of application for active thermography with inductive excitation are to be found in industrial manufacturing and in maintenance (vehicle, drive system and power plant components, jointing technique, semi-finished products, etc.).
Active thermography with inductive excitation is also called inductive thermography or eddy-current excited thermography.