NDTnet 1998 Aug, Vol.3 No.8

Abstract

TRC has a long tradition in building and maintaining systems for visual inspection in the nuclear industry. Every year, on the Swedish and Finnish markets, visual techniques (VT) from TRC are used to complement the traditional ultrasonic and eddy current methods, supplying pictures and video filmsfor analysis and interpretation of results. In addition, VT is frequently used in inspection of reactor vessels to get a rapid overview of the internals, that they are in position and are intact. TRC achieves high image quality by in-depth knowledge of the objects to be inspected and also by understanding the behaviour of the cameras in this radioactive environment.

Visual technique has always had the advantage of presenting the results in an intuitive way, by means of pictures and video films. The arbitrary element, though, regarding scanning procedure andinterpretation of results, has been high. When the visual technique is combined with traditional manipulator and scanner technology, it approaches the point where it can be considered as a NDE method equal in merit to characterise defects. In automated ultrasonic and eddy current inspection, the main emphasis is based upon manipulators guiding the transducers in a careful and reproducible manner. It is shown in the article how this, applied to VT, creates new possibilities for theperformance of calibrated, procedure-controlled inspections with enhanced resolution.

The ability to resolve small defects has been available for a long time by using microscopes and cameras, but most often with expensive and heavy equipment. By means of CCTV (closed circuittelevision) cameras and digital image processing, smaller equipment can be used with almost the samere solution. This is achieved by putting together information from many images. Examples are given of this in the article. Among the examples are underwater inspection at very high magnification. It is also discussed how advances in digital image processing and image analysis could be used in visual inspection systems as help to the operator.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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