African Fusion November 2015

NDT: digital radiography

MarcoGonzalez of GammaTec NDT Supplies in Vereeniging summarises the trends being witnessed in the industrial digital X-ray inspection systems market and highlights growth opportunities. Digital radiography: an NDT growth opportunity

W hen digital radiography was first introduced for non- destructive testing (NDT) in industrial applications, it was con- sidered to be an ideal alternative to film-based radiography. However, even the staunchest enthusiasts of digital radiography knew that acceptance in such conservative industries such as aerospace, oil and gas, and power generation would be challenging. Now, with the constantly evolving industrial digital radiographymarket at the cuspof realizing its truepotential, it is ironic that aerospace, oil and gas, and the power generation industries are providing the strongest growth opportunities. The advantages of digital radiogra- phyover film-based radiographyarewell documentedandapparent. In summary, these include: • Lower dosages are needed with smaller safety zones. • Immediate observation of radio- graphic images. • Ability to manipulate, enhance and annotate images. • Obviates the need for darkrooms and chemical development.

• Efficient data storage. • Easy to communication electroni- cally. • Ease of use. • Portability is the key to success With the incremental film-to-digital tran- sition inNDT applications, a trend that is driving and accelerating the adoption of digital radiography is portability. Espe- cially for field applications, portability has provided a different dimension to digital radiography. As digital flat panel detectors are not flexible and robust enough, they do not lend themselves to applications such as pipelineweld inspection, where computed radiography (CR) is the pre- ferred digital radiography technology.

Marco Gonzalez of GammaTec NDT Supplies in Vereeniging. With Carestream NDT’s latest product introduction, the HPX-PRO CR system, portability for field applications has taken on a new meaning. As the first step in the transition from film to digital radiography, this portable solution that targets narrow-width applications is expected to be a game changer. What does the industry need? For industry, digital radiography needs to retain the fundamentals of radio- graphic techniques, but it also needs

A digital radiograph of a 12 mm plate weld with and SNR of 111.3 measured in the parent material. This meets the SNR minimum requirements of 98 (1.4 times 70) if not measured in weld the weld metal.

to enable satisfactory and repeatable results to be obtained economically. What this means is that users of the technology need clear, unambiguous guidelines of what and how to measure andmonitor basic image quality param- eters during technique development and for subsequent production images. The various ISO 19232-5 and ASTM standards meet this need by provid- ing objective measures and guidance relative to some key image quality considerations. First is basic spatial resolution (SRb) of a digital image, which is a measure of effective pixel size and an indicator of the capability of an imaging system to resolve detail

“With Carestream NDT’s latest product introduction, the HPX-PRO CR system, portability for field applications has taken on a new meaning,” says Gonzales.

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November 2015

AFRICAN FUSION