Non destructive testing (NDT) refers to the examination of components/structures without adversely affecting their performance/usefulness. NDT techniques are relevant at the manufacturing stage, as part of quality control. They are also used throughout the life of components/structures for integrity assessment purposes.

There is not always a clear distinction between corrosion monitoring and NDT, some overlap is possible. NDT and corrosion monitoring can be used beneficially in combination and in a mutually supportive manner. In some cases, corrosion monitoring programs are only launched after NDT inspection has revealed a problem.

Industrially significant NDT methods include:

Visual Inspection,,Ultrasonic Inspection, Acoustic Emission, Liquid Penetrant Inspection, Magnetic Particle Inspection, Eddy Current Inspection, Radiography, Thermography.

References/Literature:

D.E. Bray and R.K. Stanley: "Nondestructive Evaluation", McGraw-Hill, New York, 1989.

Links:

American Society for Nondestructive Testing
www.asnt.org
with various technical articles at
http://www.asnt.org/publications/materialseval/materialseval.htm

New Zealand Non-Destructive Testing Association (NDTA):
www.winzurf.co.nz/ndta/index.htm

Popular on-line journal at:
www.ndt.net