Parallel: Shadowcast carbon replicas of diffraction parallel line gratings with spacing of 462.9 nm, 2160 lines per millimeter onto 3.05 mm grid.
Crossed: Cross line pitch spacing of 463 nm with 2160 lines/mm in both directions, cross at 90° to one another give additional accuracy to magnification checks and aid in checking distortion. Trench-type groove makes it easy to measure pitch. Ideal for calibration electron-optical magnification up to the x80000/100000 range.