Optical Comparators Calibration Services Home » Optical Comparators Calibration Optical Comparators Calibration Calibration of an optical comparator includes: Focus squareness parallel to the optical axis Table squareness perpendicular to the optical axis Perpendicularity of X to Y axis Edge detection accuracy to centerline for systems equipped with behind-the-mirror edge systems Magnification & distortion accuracy for all lenses equipped with the machine Chart angular rotation in 90 and 180 degrees Chart holds centerline in 180 degrees X & Y axes lead accuracy, every inch for the entire length of travel Sales Inspection Calibration Maintenance