Non Destructive Testing
Non Destructive Testing (NDT) can basically be defined as any inspection which is applied to a structure or component to determine it's properties or quality without damaging or impairing it's usefulness in the process (or to test without breaking it).
The aim of Non Destructive Testing should be to locate and identify any critical or important defects or conditions which could either cause failure or affect the usefulness of the subject item.
The most common areas for which Non Destructive Testing was originally developed were for detecting:
a. Manufacturing defects
b. In-Service defects
Over the years other areas of application have been added to this:
c. Measuring material thickness
d. Measuring coating thickness
e. Identifying alloys
f. Testing for correct assembly
g. Measuring fluid levels
h. Measuring mechanical properties
i. Measuring electrical properties
These areas of Non Destructive Testing application are only a sample as there are many other areas either not mentioned or are under development. The major areas methods of Non Destructive Testing used in industry today can be cathegorised as follow;
- both color contrast and fluorescent
- including metal sorting, hardness sorting, crack detection and coating thickness
- including colour contrast, fluorescent and magnetic rubber
- crack detection, thickness measurement, material evaluation
- including the use of mirrirs, magnifiers, borescopes, microscopes etc.
-both x-ray and gamma radiation
These are the most common and versatile methods that are in use today. Improvements in electronics has increased the sensitivity and versatility of these methods.