CCD Based Moire Interferometric Strain Sensor (MISS)

Abstract

The Moire Interferometric Strain Sensor (MISS) is based on the principle that gratings diffract light in preferred directions determined by their frequency. Hence by tracking the change in diffraction angle the frequency of the grating can be determined. In engineering applications, a grating attached to the specimen would change frequency as a consequence of the strain at that point. Thus the change in diffraction angle can directly be related to strain. Since for most elastic strain measurements the change in diffraction angle is very small, this paper describes the use of a CCD array to improve the sensitivity.