Non-Destructive Testing (NDT) include a wide range of analysis techniques that use electromagnetic radiation, sound wave, and other signals to assess the properties of a material, component or system without causing apparent physical damage.
Take medical X-ray for example, it is a well known NDT method in medicine. In general, most procedures in radiology (such as MRI, ultrasound, CT, etc.) are known as non-invasive diagnostic methods, meaning that no puncture of the patient's body is required for the diagnostic purpose.
In different industries, NDT methods are routinely used where a failure of a component could have a catastrophic consequence, such as in fuel piping, transportation, building structures, and hoisting equipment.
In manufacturing, welds are commonly used to join two or more metal parts. Often due to many factors, a crack may appear in the joint and welders would need to use NDT techniques like industrial radiography, CT, and ultrasonic testing to check for cracks in the metal products.
Because of their short wavelengths and deep penetrating power, gamma ray and X-ray are among the most commonly used electromagnetic radiation in different NDT applications.
Source: IAEA via Youtube
Featured image: portable X-ray generator. Credit: Wikipedia