5 Common Non-Destructive Testing (NDT) Techniques

Oil & Gas, Refining
Jan | 31 | 2017

Non-destructive testing (NDT) is widely used for quality control in the fabrication of process plant and equipment. It is a set of techniques used to evaluate the structural integrity of materials and detect any flaws that can compromise their safety or functionality.

Here are five of the most common NDT methods in use today.

Liquid Penetrant Testing – Liquid penetrant testingis one of the simpler methods used to detect defects in material. When a liquid dye penetrant is applied to a surface, it is drawn into any surface cracks or voids, thereby highlighting visible breaks in the structure.

Electromagnetic Testing – Electromagnetic testing is a category that includes Eddy Current Testing, Alternating Current Field Measurement and Remote Field Testing. These techniques can detect both surface and sub-surface flaws. Tests induce an electric current or magnetic field in the material and any defect creates a measurable response.

Magnetic Particle Testing – Magnetic particle testing is widely used for detecting surface and near-surface flaws in ferromagnetic materials. The material to be tested is magnetized. The air gaps from any defects on or near the surface cause leakages in the magnetic flux. Iron particles spread on the surface will be attracted to outline each crack and facilitate detection.

Ultrasonic Testing – Ultrasonic testing enables detection of deep and extremely small flaws within the material. Withthis method, a transducer generates ultra-high frequency sound waves through the material. When a discontinuity such as a crack or any other imperfection is encountered, part of the sonic energy is reflected. It is then measured and displayed on a screen.

Thermal Infrared Testing – Thermal infrared testing, or infrared thermography, measures and maps differences in temperature on the surface of a material using thermal imaging devices. Minute changes in temperature can be measured to detect cracks, inclusions or voids.

Honiron is an industry-leading designer and manufacturer of processing equipment, including heat exchangers, condensers, strippers, evaporators, and extractors. For more information or to speak with one of our qualified experts, contact us today.


Honiron Manufacturing is a global manufacturing solutions provider of industrial process equipment serving the sugar, oil and gas, petrochemical, carbon black, and food processing industries. Combining operational expertise, single-source capabilities and proven processes, we provide innovative, high-value manufacturing solutions that meet our client’s operational challenges - safely, efficiently, and cost-effectively.

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