Non-destructive testing (NDT) is the descriptive term used for the practice of examining materials and components in a way that does not change or destroy their usefulness. It is used at all stages of plant quality control, equipment production and for monitoring integrity of operational plant. 

NDT plays a crucial role in ensuring cost effective operation, safety and reliability of plant, with resultant benefits to the community. NDT technicians and engineers define and implement tests that locate and characterize material conditions and flaws that might otherwise cause planes to crash, reactors to fail, trains to derail, pipelines to rupture, and a variety of less visible, but equally troubling events. Benefits provided by the correct application of NDT include:

• Compliance with technical and statutory requirements

• Safety of plant and structures

• Avoidance of loss from breakdown

• Establishment of fitness for purpose

• Protection of investments through predictive maintenance.

Non-destructive testing is reliable only when undertaken to appropriate standards. To ensure this a wide range of national and international standards are documented that covers specific industry needs.

 Non-Destructive Evaluation (NDE) is a term that is often used interchangeably with NDT. However, technically, NDE is used to describe quantitative measurement and data analysis. For example, an NDE method would be used to determine information about defects such as size, shape, and orientation. NDE may also be used to predict the safe lifespan of components that possess identified defects.