Published on 01-Nov-2023

Comparison between the different Non-Destructive Testing Methods

Comparison between the different Non-Destructive Testing Methods

Non-destructive testing (NDT) is a testing and analysis technique used by industry to evaluate the properties of a material, component, structure, or system for characteristic differences or welding defects and discontinuities without causing damage to the original part. NDT is also known as non-destructive examination (NDE), non-destructive inspection (NDI), and Non-destructive evaluation (NDE).

As we know, non-destructive testing can generally be split into two areas: surface techniques and sub-surface techniques. These techniques are then categorized into various testing methods such as visual testing, liquid penetrant testing, acoustic emission testing, leak testing, radiography, ultrasonic testing, magnetic particle testing, eddy-current testing, vibration analysis, thermal/infrared testing, and laser testing.

Let’s have a look at the points which differentiate them from each other. 

Visual Testing


Oldest forms of testing

Can check for damage including cracks, corrosion, and misalignment

Liquid Penetrant Testing


Flexible technique used in the aviation industry

Can detect surface defects and structural damage in non-porous materials

Acoustic Emission Testing


An abrupt force is used

Leaks and active corrosion can be detected

Leak Testing


Involves pressurizing & immersing the test object in a liquid

detects gas (usually air) leaking from the test piece in the form of bubbles.

Radiographic Testing


can use both x-rays for thin materials and gamma rays for thicker materials

To show discontinuities in the testing object

Ultrasonic Testing


uses high-frequency sound waves to locate defects

conduct examinations and measurements on a test area

Magnetic Particle Testing


involves inducing a magnetic field in the test object

find discontinuities at or near the surface of ferromagnetic materials

Eddy-current Testing


induces an electromagnetic field in a conductive test object

measures the secondary magnetic field generated around the electric current 

Vibration Analysis 


used to monitor the vibration signatures generated by a rotating piece of machinery 


Thermal/Infrared Testing


mapping the surface temperatures of an object

used to detect damage such as corrosion, delamination, voids, and disbonds

Laser Testing Methods


Useful in detecting tiny flaws

use laser light in different ways to detect deformation on the surface of objects and computer processing to compare stressed and unstressed conditions


Are you looking for a single platform that has all the information related to Non- destructive Testing? Your search ends here. One Stop NDT has everything related to Non-Destructive Testing in one place.

Backed by professionals with unprecedented experience & the presence of more than 20 years in the NDT Market, One Stop NDT gives you a chance to freely communicate and interact with experts.

Tree PNG back


Tree PNG back




Tree PNG back


Application Notes