What Is NDT: Benefits & Applications of Non-Destructive Testing


INon Destructive Testingn the realm of equipment maintenance, the significance of testing cannot be overstated. Evaluating the materials, components, design, and structure is essential to ensure the reliability and safety of products and assets. Testing procedures can be broadly categorized into two types: destructive testing, which involves damaging or destroying the tested component, and non-destructive testing (NDT), which allows assessment without causing harm to the equipment. 

What is non-destructive testing?

Non-destructive testing (NDT) is a set of inspection techniques used to evaluate the integrity and quality of materials, components, and structures without causing any damage to the tested object. The primary purpose of NDT is to detect flaws, defects, or irregularities that could compromise the performance or safety of the inspected item. It is widely employed across various industries, including manufacturing, construction, aerospace, automotive, and more, to ensure the reliability and safety of critical components and structures.

NDT utilizes various methods and technologies to examine the internal and external characteristics of materials and components. These methods include ultrasonic testing, radiographic testing, magnetic particle testing, liquid penetrant testing, eddy current testing, and visual inspection, among others. Each NDT technique has its unique principles and applications, making it suitable for specific materials and defects.

The advantage of NDT lies in its ability to provide valuable information about the condition of an object without causing any damage, which allows the inspected item to remain functional and operational after testing. This non-invasive approach helps in identifying potential issues early on, enabling timely maintenance and repairs, and ultimately ensuring the reliability, safety, and longevity of industrial equipment and structures.

NDT can also be referred to as non-destructive evaluation/examination (NDE) or non-destructive inspection (NDI). 

Consider this scenario: a piston operating inside an engine undergoes testing to assess any defects or material degradation. Traditionally, the piston would be cut open for inspection, rendering it unusable even if no defects were found—this is known as destructive testing.

However, an alternative approach involves radiography testing. By utilizing ionizing radiation like X-rays or gamma rays, defects or material degradation can be detected within the piston. The advantage of this non-destructive testing method is that if the piston passes the inspection, it can still be used in the engine without any damage.

Where is NDT used?

Non-destructive testing finds widespread applications across various industries, offering valuable insights into component quality and machine condition without causing damage. Some of the key industries where NDT is extensively used include:

Aerospace: NDT is vital in the aerospace sector for testing castings, assessing the integrity of aircraft components, and ensuring the safety of critical parts like wings and engine components.

Automotive: In the automotive industry, NDT is employed to test the durability of piston heads, engine components, and critical parts, enhancing the overall reliability and performance of vehicles.

Manufacturing: NDT plays a crucial role in manufacturing processes, allowing quality control teams to test the integrity of components before they enter production, ensuring adherence to standards, and minimizing defects.

Medical Devices: NDT is utilized to evaluate the durability and composition of medical devices, such as stents, implants, and surgical instruments, ensuring they meet strict safety and quality requirements.

Military and Defense: In the military and defense sectors, NDT is employed for ballistics testing and analysis of firearms and artillery, contributing to the precision and effectiveness of weapons.

Packaging: NDT is used in the packaging industry to test the structure and detect potential leakages in various packages, ensuring the safety and integrity of products during transportation.

Marine Industries: NDT is crucial in the marine sector to identify corrosion and structural issues in ships, offshore structures, and underwater components, ensuring marine safety and longevity.

Power Generation: NDT is employed in the power generation industry to test welding-related defects in critical structures like pipelines, ensuring the efficient and safe operation of power plants.

Waste Management: NDT techniques are utilized in waste management to identify redeemable metals in waste materials, aiding in recycling efforts and resource recovery.

Petrochemical Industry: In the petrochemical sector, NDT is essential to test pipelines used to transport oil and other hazardous substances, ensuring the integrity and safety of these crucial assets.

Why is NDT used?

Non-destructive testing (NDT) offers numerous advantages that make it a vital tool in various industries. Some of the key reasons why NDT is used are as follows:

Reusability of Tested Components: One of the significant benefits of NDT is that it allows for the evaluation of components without causing damage. This means that the tested components can still be used after the inspection, reducing waste and minimizing costs.

Testing Components in Operation: NDT techniques can be applied to components while they are still in operation, without requiring shutdown or disassembly. This enables real-time assessments of machine conditions, leading to enhanced efficiency and reduced downtime.

Compact and Portable Equipment: NDT devices and testing equipment are designed to be compact and portable, facilitating easy on-site testing. Technicians can assess components directly in their working environment, saving time and resources.

Additional advantages of non-destructive testing include:

Ensuring Safety: NDT helps identify early signs of degradation and potential equipment failures, enabling timely corrective maintenance. This proactive approach enhances the safety of working components and reduces the risk of unexpected malfunctions.

Quality Assurance: NDT methods are invaluable for quality control in production processes. The quality assurance team can quickly analyze the output to ensure products meet required standards and tolerance limits.

Assessing Remaining Useful Life: NDT inspections can estimate the remaining useful life of machines. By understanding the rate of wear and tear, maintenance teams can optimize replacement schedules and avoid unnecessary costs.

Each non-destructive testing method has its unique applications and specifications, catering to diverse industry needs. Exploring these techniques further can provide valuable insights into how NDT contributes to various fields.

What methods are there for conducting NDT Inspections?

Non-destructive testing (NDT) offers a diverse range of techniques for inspecting components and materials without causing any damage. The choice of method depends on the specific component being tested and the desired information. Below, we explore some of the most common NDT methods widely used in various industries:

Visual Inspections: This straightforward method involves visually examining components for signs of wear and tear. It is often part of routine maintenance work and can be conducted while the machine is in operation. In advanced applications, visual testing can be combined with machine learning algorithms for efficient product quality testing.

Ultrasonic Testing: Utilizing high-frequency sound waves, ultrasonic testing is versatile and used for flaw detection, dimensional measurements, and material characterization. By analyzing sound wave reflections, defects and deterioration in materials can be identified, making it ideal for mechanical components subjected to heavy workloads.

Vibration Analysis: This technique monitors rotating components by measuring their vibrations. Different materials exhibit distinct vibration signatures, allowing for condition monitoring and predictive maintenance to prevent potential faults.

Magnetic Particle Testing: Employed to detect near-surface defects in ferromagnetic materials, magnetic particle testing utilizes the effect of a magnetic field on the material. It is widely used in industries like boiler inspection, vessel examination, and weld repairs.

Penetrant Testing: Suitable when magnetic particle testing is not feasible, penetrant testing involves spraying a liquid dye penetrant on the test area. The liquid seeps into surface defects and is then observed after the developer application, revealing any flaws.

Eddy Current Testing: Based on electromagnetic induction, eddy current testing is used for surface and subsurface inspections. It identifies defects and cavities by measuring variations in current consumption, making it valuable for a wide range of materials and components.

X-ray Inspection and Industrial Computed Tomography: Similar to medical applications, X-rays and computed tomography are employed in industrial radiography for detailed imaging of test materials. They enable real-time visualization and analysis of internal structures, aiding in quality control and flaw detection.

Apart from these widely used methods, various other NDT techniques, such as guided wave testing, laser testing, leak testing, magnetic flux leakage, neutron radiographic testing, and thermal/infrared testing, find application in scientific laboratories and specific industry operations.

Non-destructive testing encompasses a multitude of effective and specialized methods, ensuring the safety, reliability, and quality of components across various sectors. The continuous development and application of NDT play a crucial role in enhancing product integrity and optimizing maintenance strategies for efficient operations.

Who performs non-destructive testing?

The performance of non-destructive testing (NDT) relies on technicians with diverse skill sets and experience. Some NDT methods, like visual inspections, can be carried out by novice technicians with basic training and a well-structured checklist. However, specialized techniques such as industrial computed tomography demand technicians with expertise in radiology and testing equipment.

The responsibility for conducting NDT depends on what is being tested – machine or component condition, or product quality. In cases where production line output requires evaluation, the quality assurance team may handle NDT. On the other hand, in most scenarios, the maintenance team conducts the testing. In certain instances, Original Equipment Manufacturers (OEMs) may also conduct scheduled NDT tests. Organizations can efficiently manage testing intervals and record data by utilizing CMMS software. Additionally, when sensors are integrated into machines for real-time data analysis, CMMS can automatically detect signs of deterioration and trigger alerts.

The American Society for Nondestructive Testing (ASNT) plays a crucial role in accrediting qualified technicians. ASNT offers various NDT training courses, conducts exams, issues certificates, and accredits organizations in the non-destructive testing field.

Looking into the future, the multitude of developed non-destructive tests speaks volumes about the value of these methods. Conducting assessments without damaging machines and avoiding interruptions, particularly in production environments, is a significant advantage. As predictive and prescriptive analytics continue to gain popularity, the usage of NDT is expected to grow. Accurate machine condition data is vital for algorithms to predict failures and offer effective solutions, and NDT, alongside condition-monitoring sensors, provides the ideal means to achieve this objective.

What are the difficulties with conducting NDT Inspections?

Conducting NDT inspections presents unique challenges, especially when dealing with extensive pipelines and diverse composites, some of which are welded or produced using different techniques. Thorough inspection is essential to ensure accuracy and detect any potential damage or cracks that might have been overlooked.

In manufacturing, the timing of inspections during the night shift after daytime production can result in production bottlenecks and inefficient time management. If inspectors miss any issues or need to redo inspections, it can further disrupt the production process.

Common challenges in conducting NDT inspections include:

  • The Complexity of Equipment: Many NDT methods necessitate specialized and intricate equipment for accurate inspections. Regular calibration and maintenance are crucial to ensure their reliability.
  • Operator Skill and Training: The effectiveness of NDT inspections heavily relies on the expertise of operators. Specific training and a deep understanding of the NDT method and its principles are essential for accurate assessments.
  • Surface Preparation: Properly preparing and cleaning the material’s surface is vital for effective inspections. However, challenges may arise in accessing certain materials or surfaces.
  • Sensitivity to Environmental Factors: NDT inspections can be influenced by environmental factors like temperature, humidity, and electromagnetic interference, impacting their accuracy.

Here are some solutions to overcome these challenges:

  • Invest in Quality Equipment: Improve NDT inspection reliability by investing in high-quality equipment that is properly maintained and calibrated.
  • Get NDT Operators Trained and Certified: Enhance inspection quality by providing operators with adequate training and certification, improving their understanding of NDT principles and limitations.
  • Conduct Thorough Surface Preparation: Ensure effective inspections by using specialized cleaning equipment and methods to thoroughly clean the material’s surface.
  • Minimize Environmental Factors: Mitigate the impact of environmental factors on NDT inspections by conducting assessments in controlled environments or using equipment designed for such conditions.

Integration of NDT with CMMS

Computerized Maintenance Management Systems (CMMS) are software solutions that assist organizations in managing their maintenance operations efficiently. Integrating NDT data with CMMS offers several benefits:

Centralized Data Management: By incorporating NDT inspection data into the CMMS, all relevant information about assets and their condition is stored in one centralized database. This allows maintenance teams to access historical inspection data, track trends, and plan maintenance activities effectively.

Condition-Based Maintenance: NDT data provides valuable insights into the actual condition of equipment and structures. By using this data in CMMS, maintenance teams can shift from traditional time-based maintenance to condition-based maintenance strategies. This reduces unnecessary maintenance and optimizes the use of resources.

Improved Asset Performance: By regularly conducting NDT inspections and recording the results in CMMS, organizations can identify potential issues early on. Addressing these issues promptly leads to improved asset performance, reduced downtime, and increased overall productivity.

Compliance and Safety: In industries where safety is paramount, NDT data integrated with CMMS helps ensure that all assets and structures meet the necessary regulatory requirements. This minimizes the risk of accidents and ensures compliance with industry standards.


eWorkOrders CMMS, a leading maintenance management software, plays a pivotal role in the integration of Non-Destructive Testing (NDT) data. By seamlessly incorporating NDT inspection information into the CMMS platform, organizations can effectively streamline maintenance operations, track asset conditions, and optimize resource allocation. This integration empowers maintenance teams to proactively address potential issues, improve asset performance, and ensure compliance with industry standards. As NDT and CMMS integration advances, industries can look forward to enhanced efficiency, safety, and longevity in their industrial processes.

See What Our Customers Are Saying

Customer Testimonials To Read More

Customer Success

GetApp Category Leader Award for CMMS, Preventive Maintenance, Fixed Asset Management, Work Order, Fleet Maintenance, and Facility Management      #1 Rated Maintenance System for CyberSecurity      Capterra Shortlist Award for CMMS, EAM, Asset Tracking, Fixed Asset Management, Fleet Maintenance, Facility Management, Field Service Management, and Preventive Maintenance