FIFTH CANADIAN CONFERENCE ON NONDESTRUCTIVE ... - IAEA

11.4 Fully Automated Inspection
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Three major phases have been identified in moving toward fully automated real
time radiography:
1. The first phase would establish the feasibility of replacing
conventional radiographie film with real time radiography while
using the weld inspector to make all decisions regarding
acceptability.
2. The second phase would use the computer to scan over acceptable
regions of the weld image and stop at questionable areas. The
interpreter would be shown the areas and would be asked to make
a decision regarding acceptance. Image enhancement features
would be available to aid in the decision.
3. Finally, fully automated inspection would involve having the
computer make the radiographie acceptability decisions. The
computer will compare the image against a specification criteria
and make the "go" or "no go" decision.
Laboratory real time radiographie systems are currently entering the second
phase of development toward full automation. Enhancement of questionable
areas within images is possible, and software being developed will enable
computers to locate those questionable areas.
11.5 Application of the System to the Production Environment
The transition from the laboratory to the production environment presents the
single development step that must be bridged before a real time radiographie
system is placed on a laybarge. Although many systems are now capable of
producing qualified images of thick, steel sections, the functional reliability
and efficiency of the systems on a laybarge must be proven. The
following is a list of some considerations to be made in judging the functional
applicability of a system on a laybarge:
Front end of the system. Any pipe mounting band or ring must be
easily detachable to allow for passage of the pipe and miscellaneous
joints, such as valves and tees, through the system. The band or
ring must also be easily attachable and must allow for the image
collector and, if necessary, the source of radiation to travel over
or on it. Consideration must be made for concrete coating on the
pipe.
The image collector should be rugged enough to function in extreme
climatic conditions and should not be affected by the heat of cooling
evolved from the weld. Magnetic fields should not harm its function
either. If double wall exposure, single wall viewing is employed,
the radiation source and detector should track each other at 180°
separation and should remain within strict tolerances.