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AFRICAN FUSION
November 2015
NDT: digital radiography
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.
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
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,” says Gonzales.
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.
• 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.
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
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