Classification of NDT MethodsNondestructive testing is a branch of the materials sciences that is concerned with all aspects of the uniformity, quality and serviceability of materials and structures. The science of nondestructive testing incorporates all the technology for detection and measurement of significant properties, including discontinuities, in items ranging from research specimens to finished hardware and products. By definition, nondestructive techniques are the means by which materials and structures may be inspected without disruption or impairment of serviceability.

Why Conduct Nondestructive Testing?
No longer is visual examination the principal means of determining quality. Nondestructive wide spectrum of global are used to detect variations in structure, minute changes in surface finish, the presence of cracks or other physical discontinuities, to measure the thickness of materials or coatings and to determine other characteristics of industrial properties.

Current nondestructive tests are used by manufacturers to:

(1) Ensure product integrity, and in turn, reliability
(2) Avoid failures, prevent accidents and save human life
(3) Make a profit for the user
(4) Ensure customer satisfaction and maintain the manufacturer's reputation
(5) Aid in better product design
(6) Control manufacturing processes
(7) Lower manufacturing costs
(8) Maintain uniform quality level
(9) Ensure operational readiness.

Preventing Accidents and Saving Lives
Reliability to protect human lives is the most valuable reason. The greatest insurance on human safety is the extensive use of nondestructive testing and of the high order of nondestructive testing ability now available.