Patent Number: 048658006
Section: abstract

A fuel assembly grid inspection apparatus includes a precision noncontact measurement device having a source of illumination and a viewing system which defines an inspection field of view. The viewing system is adapted to view and record one or more images of an object, such as a fuel assembly grid, located in the field of view to provide information from actual measurements of the grid which can be calculated to determine whether or not it comes within acceptable tolerances of the measurements of a standard grid of the same design. The apparatus also includes a universal fixture adapted to support any one of a variety of grids of different designs within the field of view such that portions of the fixture within the field of view are substantially transparent to the viewing system. The viewing system and the fixture are movable relative to each other in X, Y, and X directions for achieving a complete inspection of all parts of the grid. Typically, the grid being inspected has at least a pair of vertically displaced fuel rod contacting dimples disposed in each of a plurality of cells defined in the grid. The dimples are inspected for perpendicularity with respect to each other by using the viewing system to view them at separate instances but from the same location within the field of view.