Roundness
Roundness vs. Equivalent Diameter plots for five eccentric wafers:
There really doesn’t seem to be a correlation between equivalent diameter and roundness. However, there does appear to be a rough downward trend in SC 016 and SC 258.
Mean Roundness vs. Wafer Number graph with error bars included:
Without the error bars, it looked like the graph bowed in the middle. With the error bars, it looks like the graph is horizontal within the error bars.
Some examples to better visualize what the roundness values mean:
