Published on 30-Jun-2022

What Is Non-Destructive Testing? Its Methods And Applications

What Is Non-Destructive Testing? Its Methods And Applications

Non-destructive testing (NDT) refers to assorted inspection methods specially developed to enable the inspectors to collect information and analyse a structure, material or component without causing any harm to the subject and not bringing up any change in it. If you are in a business that counts on non-destructive testing to examine your materials, you should be aware of the significant non-destructive testing techniques. If you have more knowledge about non-destructive testing, you can be smart enough to choose the best non-destructive testing methods based on your requirements.

If you are interested in understanding non-destructive testing, you can apply for NDT training on our website. 

And now, let's continue reading this article to learn about NDT methods and applications. 

Types of Non-Destructive Testing Methods

In Non-destructive testing, there are many techniques that are used for acquiring different types of information, and each of them needs its own sort of equipment, training sessions, preparation and proper knowledge. 

There are a lot of things that need to be understood, like some of the methods may permit performing volumetric analysis of the material, and some of them may only give them permission to analyse the surface area only. 

In the same manner, some of the NDT techniques may result in varying levels of victory as it totally relies on the choice of the sample material that is being used and on the other hand, some of the methods, for example - Magnetic Particle Testing, this particular technique will only operate on certain materials, i.e. on the substances that can be easily magnetised. 

Given below are the prominent non-destructive testing methods explained in detail. 

  • Eddy Current Testing -  Eddy Current Testing is a form of Electromagnetic testing, and it implicates detectors, who measure the magnetic field of the material for the resilience of eddy currents. It is often referred to as electrical currents. After the measurement is done, the detector is able to catch hold of any defects present in the material. Detectors especially look for any interruptions in electric current because this clearly conveys the message of the existence of defects in a material.
  • Acoustic Emission Testing - Acoustic Emission Testing is the process of using acoustic emissions to find possible defects & drawbacks existing in a material. This particular test includes acoustic energy bursts because these bursts help in demonstrating the flaws & defects. Additionally, detectors have to analyse the arrival time of a burst, its location and most importantly, its intensity to discover all the deficiencies in a material.
  • Magnetic Particle Testing - Magnetic Particle Testing, this procedure is conducted to find defects by analysing any disruption in the flow of magnetic field in a particular material. In order to perform this specific test, the detector has to induce a magnetic field in the material, which is easily sensitive to magnetisation. After the inducement of the magnetic field, iron particles are sprinkled over the surface of the material. These tiny iron particles help in revealing whether there is any presence of disruptions and also provide signals that give information about the location of the defects. 

  • Leak Testing  - The leak testing method is performed to check if there are any leakage issues in the material. If you have a vessel that has a problem with leakage, you can go for the leak testing method to identify the defects and where it is located. Detectors conduct leak testing by using pressure gauges, soap-bubble assessments etc.

  • Radiography Testing - Radiography Testing detects imperfections or flaws in a material through X-rays or gamma-rays. This type of investigation utilises a radioactive isotope or an X-ray generator so that the radiation can be transmitted into the material that is being examined and onto a detector which is like a film.  Thereon the radiation is transmitted, inspectors can glance at fundamental readings from a shadowgraph which is developed by a detector. This helps in finding out possible defects such as shifts in density.

  • Ultrasonic Testing - In Ultrasonic Testing, high-frequency waves are transmitted into the sample material to find out any changes or defects in the subject. Pulse echoes are used in ultrasonic testing. In this method, sound waves play a vital role as the sound wave is produced and transmitted into the material, and then the sound's echoes are measured to find out the imperfections or defects in the material.

Have a quick read about : Defect Size That Is Accepted In Ultrasonic Testing

  • Visual Testing - Visual Testing is all about collecting essential visual information about a substance. This is the most basic form of testing as one has to look at the material & perform a visual inspection, and that's it. However, for an in-depth visual examination, one can take help from a remote optical inspection device. This way, it will provide a piece of deeper & precise knowledge about the material. 
  • Liquid Penetrant Testing - Liquid Penetrant Testing starts with the detector applying a liquid coating containing a fluorescent dye or visible dye to the material. Then the extra liquid is removed from the surface of the material. The remaining liquid stays there, and it punctures into the surface of the material. This helps in determining any possible defects. After all this, a developer is used to pulling the solution out from the area of defects. Now, ultraviolet light is used to disclose the defects appropriately. The regular dye helps the detectors to examine the flaws through the contrast between the developer and the penetrant. 

Applications Of Non-Destructive Testing Methods

In various industries, utilisation of non-destructive testing methods takes place just to make sure that their assets, substances and systems are flawless and in good order. Those industries which are engaged in manufacturing procedures always implement NDT methods in order to confirm that their products are of great quality, integrity & are reliable. 

Also, some of the business enterprises make use of NDT methods at the time of the manufacturing process of their products, and they also use it to assure that their machines and other essential equipment are serving accurately. For instance, a mining corporation includes important systems and equipment, and they have to execute correctly so that they can deliver the expected result. Non-destructive testing enables them to review these systems without facing any stress of causing damage to these components. 

Non-destructive testing methods are widely used in various industries, such as : 

  • Marine Industry
  • Automotive Industry
  • Aerospace Industry
  • Mining Industry
  • Power Generation Industry
  • Oil and Gas Industry
  • Construction Industry
  • Chemical Industry


If you require NDT assistance, reach out to One Stop NDT anytime. Being an NDT Specific Platform; One Stop NDT work towards providing you with all the latest News, Events, Products and much more. 

Want to learn more about non-destructive testing methods? If you have any doubts or queries, please feel free to contact us.

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Application Notes

Application Notes