[yt-users] how to fix a constant density scale to all out figures?

Dear all, I am trying to visualize the density slices of my simulation output at different red-shift. But the output files (RedshiftOutput0010_Slice_z_Density.png to RedshiftOutput0058_Slice_z_Density.png) are density color coded differently. My problem is how to make the density color code scale common for all. -- Reju Sam John