Introduction to NDT (Non Destructive Testing)

NDT means Non Destructive Testing. Normally we may use two different types of testing methods such as destructive testing as well as non destructive testing for a test material. Destructive testing means we must destroy that particular test material and detect whether some defect is there or not.  In this case we cannot use that material afterwards. So we are going for NDT. Here we are not doing any harm to the test material so that we may reuse it. NDT mainly follows two different standards.

·       American Standards (ASNT)

·       British Standards.

In NDT we are mainly dealing four different types of testing methods.

Ø Ultrasonic Testing (UT)

Ø Liquid Penetrant Testing (LPT)

Ø Magnetic Particle Testing (MPT)

Ø Radiographic Testing (RT) 

Ultrasonic Testing (UT)

We are mainly using the Ultrasonic sounds waves for the testing. This method is commonly used for finding out the internal discontinuities present inside a test material. The sound waves will passes through the test materials and produce an echo.

Liquid Penetrant Testing (LPT)

LPT is the technique used for finding out surface discontinuity by applying a Penetrant on the surface of the test specimen.

Magnetic Particle Testing (MPT)

MPT also used for finding out surface discontinuity by utilizing the test specimens magnetizing property.

Radiographic Testing (RT)

RT is used for finding out internal discontinuity such as porous, cracks, voids. etc. This is done by making use of electromagnetic waves. And an image will be produced on the radiographic film. By analyzing the film we are able to find out the defect.