03/05/2016
Nondestructive Testing is one part of the function of Quality Control and is
complementary to other long established methods.
By definition non-destructive testing is the testing of materials, for surface or internal
flaws or metallurgical condition, without interfering in any way with the integrity of the
material or its suitability for service.
The technique can be applied on a sampling basis for individual investigation or may
be used for 100% checking of material in a production quality control system.
Whilst being a high technology concept, evolution of the equipment has made it
robust enough for application in any industrial environment at any stage of
manufacture - from steel making to site inspection of components already in service.
A certain degree of skill is required to apply the techniques properly in order to obtain
the maximum amount of information concerning the product, with consequent feed
back to the production facility.
Non-destructive Testing is not just a method for rejecting substandard material; it is
also an assurance that the supposedly good is good. The technique uses a variety of
principles; there is no single method around which a black box may be built to satisfy
all requirements in all circumstances.
What follows is a brief description of the methods most commonly used in industry,
together with details of typical applications, functions and advantages. The methods
covered are:
• Radiography
• Magnetic Particle Crack Detection
• Dye Penetrant Testing
• Ultrasonic Flaw Detection
• Eddy Current and Electro-magnetic Testing
However, these are by no means the total of the principles available to the N.D.T.