NON-DESTRUCTIVE TESTING:
A TECHNICAL DEFINITION
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INTRODUCTION
Non-destructive Testing (NDT) is a method of examining the strength of an object without rendering the object useless. Professionals use NDT in order to locate problems in materials which could possibly cause large accidents or failures. The benefits of NDT are an inexpensive form of effective quality control that will not affect the future ability of the object to function. There are many forms of NDT, including visual, penetrant, magnetic particle, electromagnetic, ultrasonic, acoustic emission, and leak testing. Non-Destructive Testing is similar to Non-Destructive Evaluation (NDE), however NDE does more than just find flaws in parts, it also measures and quantifies them. Compared to the traditional crash test, NDT is a rather inexpensive form of testing machines made up of expensive components, such as Formula 1 race cars. Formula One racing teams would rather not spend millions of dollars building a highly specialized race car only to destroy it in a crash test. The more efficient way to test the car’s strength would be to examine individual pieces of the car with NDT and learn how they can make the car stronger or lighter.
HISTORY
The earliest forms of non-destructive testing were used on railcar components, specifically wheels and axles. A component to be examined would be dipped in brightly colored dye so that the dye could be absorbed into miniscule cracks in the part. After the surface dye was removed, the component would be powdered, and dye from the cracks would seep out to reveal defects in the material. This method is now known as dye penetrant testing. Early testing methods were crude, but as NDT technology became better, testing methods were able to detect more and more part defects. Even though the defects had always been there and the parts were just as strong, the
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