Effects on absolute moiré contouring by using gratings with different period and profile and rotating angles

Effects on the absolute moiré contouring systems from using different period and profile gratings and rotating angles are described in this paper. It was found that by choosing a different period of the grating or the rotating angle, different resolution and accuracy of the measurement can be obtained. So, for objects with different height or depth, different period of grating or rotating angle should be chosen to ensure accuracy of the measurement. The square wave intensity grating with small period can be treated as a sinusoidal wave intensity grating in the absolute moiré contouring system. A few objects with different shapes and dimensions have been used as samples to verify the above conclusion.