Optical comparators are used for taking precise 2D measurements of a part or workpiece. The magnified silhouette of a part is projected on a screen with an X- and Y-axis. Measuring graduations are commonly superimposed over the projected silhouette of the workpiece or feature to determine the measurement. These optical comparators are commonly used in machinery manufacturing, including aviation, aerospace industry, watches and clocks, electronics, and in research and detection metering stations.