NDT is Non-Destructive Testing. As the name suggests, it is a test carried out without destroying the test object. You may be familiar with various tests carried out on human beings such as x-rays, sonography, MRI etc. These are carried out on human beings without any damage to their bodies.
Similarly, all engineering materials and manufactured products are tested by various NDT methods. This can be done before, during and after manufacturing process. Their purpose is to ensure that these products work successfully and remain trouble-free during operation. For example, we can test welding plates and pipes before welding, during welding and after completion of welding. These tests are non destructive in nature.
NDT is part of every operational industry including steel plants, automobiles, aviation, sheep building, power, oil & gas, and others.
In NDT, there are various methods and techniques such as ultrasonic testing, radiographic testing, magnetic particle testing, liquid penetrant testing, eddy current testing, radiographic testing & film interpretation, visual testing, infrared thermography, leak testing, neutron radiography, vibration analysis, and acoustic emission testing. One has to choose the most appropriate method as per the component to be tested. Different methods of selection according to shape, size, material composition, internal structure, conductivity and other properties.
Out of these methods, some are basic & widely utilised methods. These are ultrasonic testing, radiographic testing, magnetic particle testing, liquid penetrant testing, eddy current testing, radiographic testing & film interpretation, visual testing.