Radiography is divided into two major segments – conventional and digital. Digital radiography is an advanced radiography technique that has opened a world of possibilities. There are four major types of digital radiography which are discussed in another blog.
Here, we will discuss an overview of computed radiography.
Computed Radiography is a type of digital radiography that involves capturing digital pictures using a flexible phosphor Imaging Plate (IP) rather than traditional photographic film.
Computed radiography uses radiation absorption to trap electrons at different energy levels through the process of photostimulable luminescence.
It has significant advantages for inspection jobs since it eliminates the need for consumables and dramatically reduces the time required to create a picture.
This topic is an important part of the oil and gas courses for mechanical engineers.
Computed Radiography Technique
The computed Radiography technique follows three major steps:
- An imaging plate is exposed to X-ray or gamma radiation instead of film.
- The scanner digitizes the image plate, which is then erased for immediate reuse.
- After that, the digital picture is presented on a computer monitor for analysis using specialist software.
A brief explanation of the entire method
When imaging plates are subjected to X-rays or gamma rays in computed radiography, the energy of the incoming radiation is stored in a specific phosphor coating. The scanner, a piece of specialized equipment, is then used to read the latent picture from the plate by activating it with a very precisely focussed laser beam.
When stimulated, the plate produces blue light following the amount of radiation received during the exposure.
The light is then detected by a photomultiplier (PMT), a susceptible analogue device, and transformed to a digital signal by an analogue-to-digital converter (ADC). The resulting digital X-ray picture may then be seen and evaluated on a computer display.
In any online course for piping engineering, the NDT methods account for a significant evaluation aspect.
When can you choose Computed Radiography Technique?
CR technology is essentially a digital substitute for traditional X-ray film. Imaging plates are utilized in the same radiographic inspection procedures and techniques as film, and they are likewise available in various system classes (image quality) with varying needed exposure durations.
However, with CR technology, it is not only the imaging plate type that influences picture quality; the scanner’s scan parameters are also important.
The resolution capabilities of the scanner (essential spatial resolution), in particular, is crucial in determining picture quality.
Advantages of Computed Radiography
- Phosphor Imaging Plates are reusable.
- There is no need for chemical processing or a darkroom.
- Plate exposure periods are generally shorter than film exposure times.
- ScanX View Software provides tools for optimizing image quality.
- Digital data is readily saved and disseminated.
To know more about different NDT methods and other vital information as a part of oil and gas training courses online, check the Oil and Gas Piping Engineering course.