Nondestructive Testing and Evaluation

Abstract

Nondestructive testing (NDT), also called nondestructive evaluation (NDE) and nondestructive inspection (NDI), is testing that does not destroy the test object. The activ-ity primarily involves looking at (or through) or meas-uring something about an object to determine some property of the object or to determine whether the object contains irregularities, discontinuities, or flaws. The terms irregularity, discontinuity, and flaw can be used inter-changeably to mean something that is questionable in the part or assembly, but specification, codes, and local usage can result in different definitions for these terms. As all these terms describe what is being sought through testing, inspection, or examination, the term NDE (non-destructive evaluation) has come to include all NDE used to find, locate, and sizing flaws and allow the investi-gator to decide whether or not the object or flaws are acceptable.A flaw that has been evaluated as rejectable is usually termed a defect.