The activity of non-destructive testing carried out by accredited laboratories involves the application of the various non-destructive testing methods (NDT) to any type of material, product or article that needs to be characterised, from the point of view of its obvious or hidden defect, without its destruction or substantial modification being caused during the examination.

The following methods can be used to carry out tests:

• Gammagraphs and X-rays
• Ultrasonic
• Penetrating liquids
• Magnetic methods
• Parasitic (or induced) currents
• Mass spectrometry (for leak detection)
• Extensometry
• Thermography