Specify the Y-scale for Variability Chart

Stat > Quality Tools > Variability Chart > Scales

Specify a log transformation and whether you want Minitab to display the same Y-scale for multiple charts.

Log transformation

A logarithmic scale linearizes logarithmic relationships by changing the axis, so that the same distance represents different changes in value across the scale. For example, in the scatterplot with the untransformed Y-scale, the function is not linear. When you transform the Y-scale to logarithm base e, the form of the data is linear.
Untransformed Y-scale
Transformed Y-scale (log base 10 transformation)

Same scale

Use the same Y-scale across all graphs.