NDT Non-Destructive Testing

What are the techniques used for "NDT" Non-Destructive Testing?

Visual examination (VT) Analysis conducted with the naked eye by an operator expert in the defectology of the examined component
Radiography (RT) Use of X-ray or gamma radiation. Result visible on film
Liquid penetrants (LPI, PT) Application of a liquid that penetrates defects by capillarity. Enhancement of the visibility of the defect through chromatic contrast
Magnetoscopy (MPI, MT) Application of a magnetic field on ferromagnetic materials. The defects introduce variations in the field flow lines that can be visualized with special powders
Ultrasound (UT) Analysis of ultrasonic waves reflected or transmitted within the component
Infrared thermography (IT) Analysis of thermal emission in the infrared band by a body. The defect generates an alteration of the thermal field
Induced currents (ET) Analysis of the currents induced in a body (conductor) following the approach of a probe which generates an alternating magnetic field. The defect is seen as a "disturbance" in the propagation of induced currents.

What are NTD? Non-destructive tests on materials

Non-destructive testing (identifying acronyms: CND, PND, NDT, NDE) are non-invasive analysis techniques used to evaluate the integrity of a material, a component, a complex structure and some geometric characteristics (e.g. thickness and corrosion )