Non Destructive Testing(NDT), Non Destructive Evaluation (NDE) and Non Destructive Inspection (NDI) are the terms used to correspond the methods which are based on the implementation of physical principles applied for the intention of components or material or systems characteristics determination and for detecting and assessing the inhomogeneities and harmful defects without impairing the usefulness of such materials or components of systems.
NDT plays an important role not only in quality control of the finished product but also during various stages of manufacturing. NDT is also used for condition monitoring of various items during operation to predict and access the remaining life of rhe component while retaining its structural integrity. NDT ensures optimum utilization of the components without compromising the safety aspects. The use of automated devices for effective testing and microprocessors for data acquisition & processing have immensely improvised the condition monitoring on complicated plants and components.
The dependency of the operator for routine inspection is decreased and therefore, the person can focus on the technological aspects. Due to such factors, there is cost and time saving and improvement in the reliability and precision of the results acquired. There are various types of NDT methods, from simple to intricate. Visual inspection is considered the most simplest method. Surface imperfections that are not visible to the eye can be revealed through magnetic or penetrant methods. If you find serious surface defects, then there is little point in moving further to the more complex inspection of the interior by the methods such as radiography or ultrasonics.The main NDT methods include Liquid Penetrant Testing, Radiography Testing, Visual or Optical Inspection, Ultrasonic Testing, Magnetic Particle Testing, Helium Leak Detection, Helium Leak Detection, etc.