As industrial radiography continues to move away from film, many NDT departments are evaluating whether Computed Radiography (CR) or Digital Radiography (DR) is the better fit for their inspection program. Both technologies produce digital radiographic images, eliminate chemical film processing, and improve data management; but they do so in different ways.
The right choice depends on your inspection requirements, workflow, production volume, and applicable codes and standards. Understanding the strengths of each technology can help you make an informed decision before investing in new equipment.
What Is Computed Radiography (CR)?
Computed Radiography uses a photostimulable phosphor imaging plate (IP) housed inside a protective cassette. During the exposure, the imaging plate stores a latent image. After the exposure is complete, the cassette is placed into a CR scanner where a laser reads the plate and converts the stored information into a digital image.
Once scanned, the imaging plate is erased and reused for future inspections.
For companies transitioning from film, CR often feels familiar because the exposure process remains largely the same. The primary difference is that the image is scanned electronically rather than chemically processed.
What Is Digital Radiography (DR)?
Digital Radiography replaces the imaging plate with a Digital Detector Array (DDA). The detector captures the radiographic image during the exposure and transfers it directly to the acquisition software for immediate review. Because there is no scanning step, inspectors can verify image quality within seconds and move directly to the next inspection. This streamlined workflow makes DR particularly attractive for applications requiring high inspection throughput.
CR vs. DR: What’s the Difference?
Although both technologies produce digital images, the biggest difference is how those images are captured and reviewed.
| Feature | Computed Radiography (CR) | Digital Radiography (DR) |
|---|---|---|
| Image Capture | Imaging Plate (IP) | Digital Detector Array (DDA) |
| Image Availability | After scanning | Immediate |
| Workflow | Two-step process | Direct digital capture |
| Detector | Flexible imaging plates | Rigid flat panel detector |
| Inspection Speed | Moderate | High |
| Best Suited For | Field work, varied geometries, moderate production | High-volume production, repetitive inspections |
Neither technology is inherently better. The right choice depends on the inspection being performed.
Image Quality
One common misconception is that DR automatically produces better images than CR. Image quality depends on several factors, including detector performance, exposure technique, source size, geometric unsharpness, scatter control, and image processing. Both CR and DR can produce high-quality digital radiographs when used correctly and in accordance with applicable inspection procedures and code requirements. The objective is not simply obtaining a clear image but producing one that satisfies the required image quality indicators (IQIs), sensitivity requirements, and acceptance
criteria for the inspection.
Workflow and Inspection Speed
The most noticeable difference between CR and DR is workflow. With CR, every exposure requires the imaging plate to be scanned before the image can be evaluated. While modern scanners process images quickly, this additional step naturally increases inspection time.
With DR, the image is available almost immediately after exposure. Inspectors can verify positioning, exposure technique, and image quality before moving to the next part, reducing downtime and minimizing retakes. For facilities performing large numbers of inspections each day, that increase in
efficiency can have a significant impact on productivity. Detector Flexibility CR continues to offer an important advantage in applications where detector flexibility is critical. Imaging plates are available in multiple cassette sizes and can often be positioned in areas where a rigid flat panel detector cannot, making CR well suited for many pipe inspections, complex weld configurations, and field applications. DR detectors are rigid electronic devices that require adequate space for positioning. While detector designs continue to improve, component geometry should always be considered when selecting a system.
Choosing the Right Technology
When evaluating CR or DR, consider the following questions:
– What types of components are being inspected?
– What codes or customer specifications must be met?
– Are inspections performed in the field or in a production facility?
– How many exposures are completed each day?
– Is inspection speed a priority?
– Will detector flexibility be important?
Answering these questions often makes the choice much clearer.
Organizations upgrading from film or requiring flexible detector sizes frequently find CR to be an excellent solution. Facilities focused on production throughput and immediate image review often benefit from DR.
Industrial Radiography Solutions from TED
Selecting a digital radiography system involves more than comparing specifications. Detector technology, software capabilities, X-ray source compatibility, and inspection requirements all play an important role in overall system performance.
TED supplies industrial radiography solutions from leading manufacturers, including:
Computed Radiography
– Carestream
– Fujifilm
– Waygate Technologies
Digital Radiography
– Carestream
– NOVO
– Waygate Technologies
Industrial X-ray Systems
– Comet
– Gulmay
Whether you’re replacing film, expanding your digital capabilities, or building a new radiography system, our technical sales team can help identify the equipment that best fits your application and inspection requirements.
Final Thoughts
Computed Radiography and Digital Radiography are both proven technologies used throughout the NDT industry. Each offers distinct advantages depending on the inspection environment and workflow.
CR provides a familiar process, flexible imaging plates, and a practical transition from film. DR offers immediate image acquisition and increased efficiency for high-volume inspections. The best system isn’t determined by the newest technology; it’s determined by the demands of your inspection program. By understanding how each technology works and where it performs best, you can select equipment that supports consistent image quality, efficient workflow, and long-term reliability.
Need Help Choosing the Right Radiography System?
Test Equipment Distributors provide industrial radiography solutions and technical support for customers across manufacturing, aerospace, energy, petrochemical, and general industrial NDT applications.
To learn more contact our team today.
800-962-1788
