What Is Non-Destructive Testing?

Exploring the Definition, Methods, and Applications of Non-Destructive Testing (NDT)

Do you ever wonder how engineers and specialists ensure structures like bridges, rockets, or medical implants are free from hidden flaws?

Enter non-destructive testing (NDT) — the powerful technology that certifies the integrity and safety of critical components. 

NDT specialists work to secure the reliability and safety of structures and objects we depend on every single day. Read on to explore more about non-destructive testing, including the most common methods and applications across various industries. 

What Is the Meaning of NDT?

Non-destructive testing (NDT) describes a collection of techniques used to evaluate the properties of a material, component, or system without causing damage. 

Think of the process as giving a material a thorough examination without ever making a single scratch — all in the name of quality assurance.

NDT, also referred to as non-destructive evaluation or non-destructive inspection, plays a vital role in ensuring the safety, reliability, and quality of various structures and objects across numerous industries. 

Non-destructive testing is mostly used to test the reliability of:

• Machinery and equipment

• Minerals and chemicals

• Consumer products

• Construction materials

• Environmental testing

When NDT technicians or engineers perform a non-destructive inspection, they are mainly looking for 3 types of defects:

• Surface defects: holes, cracks, pitting, etc.

• Internal defects: wear marks, porosity, cracks, thickness variations, etc. 

• A non-conformity with the specifications: Incorrect dimensional measurements, surface finish, angles, etc.

Why Is NDT a Vital Inspection Method?

Non-destructive testing is a vital inspection method due to its:

• Wide range of applications: NDT techniques can be used on various materials like metals, plastics, composites, and concrete. The versatility of the examination allows them to inspect everything from welds in pipelines to cracks in aircraft wings, helping to prevent catastrophic failures, like airplane and locomotive crashes, or pipeline leaks and explosions.

• Focus on internal flaws: NDT methods aim to detect hidden defects like cracks, voids, inclusions, and corrosion that might not be visible on the surface, working to prevent catastrophic failures.

• Safety and cost-effectiveness: By proactively identifying flaws, NDT helps prevent accidents and costly repairs or replacements by promoting safety.

NDT serves as a crucial step to ensure the quality, safety, and reliability of products and structures across different sectors. One of the most useful aspects of NDT is that its methods preserve functionality. Unlike destructive testing methods, break, or compromise material, NDT allows the component to remain usable after inspection.

What Does NDT Mean in Manufacturing?

Specifically for manufacturing, NDT can be used at any point of a product’s life cycle to:

• Help manufacturers ensure their product is meeting quality standards

• Lower production costs

• Save time by detecting problems before they become catastrophic

• Help manufacturers monitor their processes and identify problems that might otherwise go unnoticed

Coordinating and managing NDT inspections can be a hassle. Without a streamlined process in place, non-destructive testing can quickly and easily overlook defects, increase maintenance costs, and more. Let UpKeep’s CMMS solution help streamline your industry’s NDT processes. Request a demo today.

Visual Inspection: The Most Common Type of Non-Destructive Testing

There are many types of non-destructive testing, some used more often in specific industries than others. However, one NDT method used widely across nearly all industries is visual inspection.

Visual inspection takes into account the welding quality of material, component, structure, or system, and looks for the presence of any:

• Corrosion

• Degradation

• Surface defects

• Foreign materials; and

• Blockages 

If any are found, the NDT inspector will recommend control measures to ensure a safe site and asset. 

Despite its name, visual inspection tests are more than just looking at an object and deciding that it’s unsafe for use. Often, visual NDTs require magnifiers, borescopes, cameras, or other optical tools for direct or remote viewing.

Although special equipment may not always be needed for a visual inspection, it does demand specialized training to ensure the inspector knows what to look for as they visually evaluate the asset.

Industries That Rely on Non-Destructive Testing

According to the Bureau of Labor Statistics, the following industries utilize non-destructive testing most frequently:

• Architectural, Engineering, and related services

• Aerospace, Aviation, and Aeronautics

• Machinery manufacturing

• Transportation equipment manufacturing

• Power Generation (nuclear, wind, electric)

• Oil and Gas and Petrochemical

• Chemical

• Scientific research and developmental services

• Computer and electronic product manufacturing

• Infrastructure

• Maritime/Marine/Underwater

Other industries that manufacture a product that relies on quality control and assurance to be safe for companies and/or consumers may also utilize non-destructive testing.

4 Common Methods of Non-Destructive Testing

Globally, the non-destructive testing market was valued at over $20 billion in 2023 and was expected to register a compound annual growth rate of 7.9% between 2023 and 2030.

The list of non-destructive testing methods is long. Various industries rely on different NDT methods or techniques to evaluate products or assets for characteristic differences of defects and discontinuities without causing damage.

Although there are many NDT methods used by different industries, there are 4 common methods many industries use time and time again:

1. Ultrasonic testing

2. Magnetic particle testing

3. Liquid penetrant testing

4. Radiographic testing

The NDT method used may vary depending on the specific material, the type of defect being inspected, and the desired level of detail.

#1: Ultrasonic Testing (UT)

In this method of non-destructive testing, high-frequency sound waves are transmitted in an attempt to penetrate the material and analyze its internal structure. 

The most commonly used ultrasonic testing technique is called pulse echo. This technique introduces sound waves into a test object and any defect or changes in material properties will cause the waves to reflect or refract. 

Any reflected sound waves are analyzed by NDT technicians and used to determine the location, size, and nature of internal flaws.

Ultrasonic testing is highly effective for detecting cracks, voids, and delamination in the tested material. While UT techniques are portable, consistent, and can detect both surface and subsurface defects, training this technique is more extensive and expensive than other methods of NDT. Additionally, ultrasonic testing can be difficult to use on certain materials. 

#2: Magnetic Particle Testing (MPT)

Magnetic particle testing, sometimes referred to as magnetic particle inspection, is used to detect surface and near-surface flaws in ferromagnetic materials. 

An NDT technician will magnetize the asset under inspection and apply fine iron particles to the surface of the material. These particles will accumulate at areas where magnetic flux leakage occurs, indicating a surface or near-surface flaw.

The technician then observes the pattern formed by the iron particles to determine the location, size, shape, and severity of the defects.

Magnetic particle testing is extensively employed across industries — including aerospace, automotive, and heavy engineering — to identify defects that pose risks to component safety and integrity. 

Although heavily used, MPT does present some limitations, including:

• Requires a skilled inspector

• Detects only surface and near-surface defects

• The asset being tested must be ferromagnetic

Despite these potential disadvantages, MPT is a fairly low-cost testing option. It’s also portable and presents a simplified way to inspect irregular shapes. 

#3: Liquid Penetrant Testing (LPT)

Liquid penetrant testing utilizes a colored or fluorescent liquid to reveal surface-breaking defects. The technician will apply the liquid to the surface of the asset, which seeps into cracks and other openings. Then, a developer is used to draw the liquid out, making any defects visible under ultraviolet light. 

LPT is a cost-effective and efficient method for detecting tight cracks, surface porosity, and leaks in various materials, including metals, ceramics, and plastics. It’s a relatively inexpensive form of non-destructive testing and allows parts or materials with complex shapes or large volumes to undergo NDT inspections.

This method of non-destructive testing is commonly used in the aerospace industry.

#4: Radiographic Testing (RT)

Similar to how X-rays work in medical imaging is how radiographic testing works as an NDT method.

Radiographic testing utilizes X-rays or gamma rays to create an image of the internal structure of a material on film or digital sensor so technicians can visualize internal defects like cracks, porosity, and inclusions. 

Light or dark areas on the film or detector indicate material thickness and density changes in the material. 

Radiographic testing is especially useful for inspecting welds, castings, and thick components, making it a common choice for those in the gas and oil, automotive, and aviation industries. 

While RT is portable and allows for full volumetric examinations, it does present a radiation hazard and is relatively expensive compared to other NDT methods. It also requires a significant setup and does not indicate depth, which can present a problem for some assets. 

Let UpKeep Help Streamline Your Non-Destructive Testing Processes

Non-destructive testing is vital for ensuring the safety and reliability of equipment, materials, and infrastructure across many industries that touch our everyday lives. 

However, managing NDT procedures efficiently can get difficult quickly, especially without the right tools. 

A computerized maintenance management system (CMMS) offers a powerful solution to streamline your non-destructive testing processes.

While a CMMS cannot perform NDT for you, it can help coordinate and manage testing and inspections, leading to improved reliability, enhanced safety, and reduced maintenance costs. 

UpKeep offers a handful of features that will help your manufacturing facility perform reliable non-destructive testing:

Scheduling and Managing 

Use UpKeep to schedule and manage NDT procedures for specific equipment based on predefined intervals, manufacturer recommendations, or risk assessment findings. With UpKeep, you can:

• Create and manage a centralized schedule for non-destructive testing tasks to avoid overlaps with other critical maintenance jobs.

• Prioritize non-destructive testing tasks based on their importance and urgency to ensure essential testing procedures are not missed.

• Send automated reminders and notifications for upcoming non-destructive testing activities, reducing the chances of missing any crucial tests.

Asset Tracking

UpKeep’s asset management feature allows you to associate non-destructive testing with specific equipment or machinery, making it easier to track the testing history of each asset. 

Technicians can use this feature to update work orders in real time, capturing updated inspection results, findings, and accommodations directly within the CMMS, allowing for immediate decision-making.

Data Management

UpKeep helps with data management for non-destructive testing by providing a centralized platform to store and analyze NDT-related data. 

Through UpKeep’s DataHub feature, you can collect, standardize, and automate data-driven asset operations. This allows you to input and organize NDT inspection reports, results, and maintenance actions in one place so it’s easy to access and reference whenever necessary.

Need help transitioning those data points into the next steps?

UpKeep’s tools offer ways to efficiently manage and transform data into actionable insights. You can visualize NDT data on dashboards, track trends, and trigger work orders based on inspection results. 

By utilizing UpKeep for NDT data management, you can improve the efficiency of your maintenance processes and make more informed decisions based on the insights derived from the data. 

Non-Destructive Testing Software and Equipment Integration

UpKeep provides integration tools to streamline maintenance and reliability processes, including the ability to integrate non-destructive testing equipment and software with our Asset Operations Management Platform.

By doing so, you can enhance your maintenance operations by incorporating predictive maintenance strategies and ensuring equipment reliability.

Avoid sinking unnecessary time and resources into keeping track of necessary maintenance schedules. Optimize your NDT with the help of UpKeep.

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