Abstract: An inspection system for automatically documenting and verifying the position and dimensions of holes in a flat sheet metal workpiece. The system includes a transparent, light diffusing inspection table upon which the workpiece is laid. A ball screw-driven yoke travels continuously along the inspection table in the Y direction and includes a bottom bar for positioning a source of illumination below the table and a top bar for positioning a plurality of optical sensor arrays above the table. The optical sensor arrays are responsive to the presence (or absence) of light energy which is diffused by the table. A detector is interconnected to the sensor arrays to detect light-to-dark and dark-to-light transitions which are representative of the edge of a hole. The transition data is read and stored in a microcomputer for subsequent display and/or print out.