Throughout my career in NDT consulting, there’s one question that gets asked more frequently as the years go by: “Can our operation change to Computed Radiography?” This question is a bit like asking how a piano works. The basic functions are easily understood, but the actual motions of operation are much more complicated. Like a piano, Computed Radiography has lots of moving parts that are unseen by even a skilled user. Parts that spark little interest from the chair in front of the keyboard. I am no musical master or even a musical novice, however, I can shed light on the many moving parts of Computed Radiography.
To answer the common question; yes, if you are willing to put in the groundwork, your operation could likely switch from traditional Film Radiography to Computed Radiography (CR) with very little changes. That is primarily due to the similarities between film and CR. Unlike other digital modalities, the exposure medium (film replacement) is flexible and fits into cassettes. The exposure technique is also similar, though shot times tend to be shorter. The ‘retrieve and process’ stage also bears some likeness to traditional film since both create a type of ‘latent image’ that must be processed before results are produced.
There are some hidden factors in CR program administration, but radiographic results mostly come down to the skill of the technician performing the test. CR is even capable of producing results aligned with film, assuming the appropriate equipment and settings are used. Herein lies the two largest hurdles with CR: equipment selection and technician training.
Which Computed Radiography System Do I Choose?
Not all Computed Radiography equipment is created equal. In fact, CR equipment is generally engineered with a specific use in mind. That means the options on CR equipment can vary greatly from brand to brand and model to model. Some are designed with the highest of resolution in mind which makes them perfect for specific jobs but may limit their usefulness in other applications. Other units are engineered for ease of use with minimal training. An idea that makes repeatability simple but can also take away important system settings, limiting its usefulness.
Which system is right for you? That is another simple question with a complicated answer. Only an appropriately qualified NDT consultant can answer that question and only after seeing your operation. High resolution and little technical training sounds like an ideal option, but those don’t exist on just one unit.
Like most things in life, there are trade-offs made from one factor to another. High adjustability options generally mean more training to learn their uses. Little adjustability may mean less training for technicians, but also puts a limit on usefulness. Likewise, portability generally puts limits on the equipment’s physical size, potentially limiting the size of images produced. Equipment selection depends on many factors, all of which play a small, but noticeable part. Choosing the wrong CR scanner could mean the difference between an effective operation and a six-figure paper weight.
Technicians Need Proper Training in Computed Radiography Systems
Regardless of the scanner you choose, training is a must. Manufacturers offer training packages at various costs which I regard as an absolute necessity. These packages usually outline normal operation, support options, basic calibration, and equipment care at a minimum. They are not to be considered all-inclusive. A well-rounded supplemental training program is necessary to inform technicians of an employer’s specific operation.
These programs, unfortunately, are scarce in the industry. My experience tells me that there are only a few NDT providers in my area who have an internal training program on CR like Braun Intertec. It simply costs too much to develop and implement for many companies to consider. Most NDT providers depend on the technicians to sort out their own training in a ‘throw them to the wolves’ type of experience. I know all of this because that’s how I got my first experience in CR. The site had a CR system and I was dispatched to learn the unit on my own. If that sounds shocking, just know that service providers are doing this every day while expecting the client to pay the bill.
As a result of this unstructured system, some technicians have gotten to the point of frustration where they tell the client that CR just can’t be done. When in reality, if they had the proper training, CR could have been implemented. This gap in program structure leaves more and more fabricators, constructors, foundries, and other manufacturers behind the curve with CR. While the industry takes off in a new direction, those service providers are leaving their clients with old techniques that are becoming antiquated.
NDT Service Providers are Often the Best Option
Consulting can be a good start to a sound CR program, but many of my readers hire a service provider, like Braun Intertec, to manage their NDT. In that situation, a little research can go a long way. If you build equipment to a code, it will either specify NDT requirements or give you another code for NDT. It may take a few steps, but you’ll find all the requirements for certification, CR system qualification, and system maintenance. Anyone already running an NDT program only needs to research documents you should already know. Whether you’re a client or an NDT service provider, we have a responsibility to our customers and end users to provide a compliant product. Anything less is unacceptable.
Computed Radiography Webinar
Interested in learning more about the transition from traditional film to computed radiography? Click the link below to sign up for a webinar with the author, Wesley Soape.