Investigation of Errors in Non-Contact Measurement of Fuel Assembly Head Height Variations Using the Parallax-Shift Method with an Arc-Trajectory Television Camera

The article presents a study of errors arising in non-contact measurement of fuel assembly head height variations using the parallax-shift method under conditions of arc-shaped motion of a television camera. The primary sources of error are examined, including radiation-induced and noise-related distortions of the video stream, contour detection inaccuracies, subpixel deviations of circle centers, geometric imperfections of camera motion, and variations in camera orientation. A model describing the influence of these factors on the final height measurement accuracy is developed. The sensitivity of height estimations to key system parameters is analyzed. The study demonstrates that the method maintains metrological reliability under typical operational deviations characteristic of nuclear power plant environments.

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