Optical profile projectors, also known as shadowgraph projectors, are widely used in manufacturing and engineering industries for the measurement and inspection of intricate shapes and profiles. These machines use an optical system to project an enlarged image of a component onto a screen, allowing the operator to compare the projected image with a standard template or profile to check for deviations in shape and size.
https://www.optomechengineers.com/optical-profile-projector/