Fig. 4: MeasureIce generated calibration curves with and without a 10 nm amorphous carbon cryo-EM grid backing.
From: MeasureIce: accessible on-the-fly measurement of ice thickness in cryo-electron microscopy
The curves are linear if fractional intensity is plotted with a log scale and the effect of the carbon backing is to shift the origin of the line but not its slope (the ALS coefficient) so only the reference intensity (I0) need be set to that measured for just a carbon film for ice thickness measurement with carbon backed grids.
