Casting a pattern of light on a part and viewing that pattern at a different angle through a grating with the same pattern creates a moire pattern that can reveal small changes in the part's shape. This article tells how this phenomenon can be used by machine vision systems to measure part dimensions or pinpoint variations from a specified contour.
Imported from the CTE archive to seed discussion on MFGAxis.
Originally published on CTE: 1996-02-01
CTE source: https://ctemag.com/articles/measuring-moire/
Legacy path: /articles/measuring-moire