you should take into account:

- a density of 0.11 for Zone I is only valid, if the density for Zone VIII is valid, too. Otherwise you will have to adjust development time and thus will get another density for Zone I, too

- The measurement characteristics of your densitometer must match the characteristics of your enlarger. If your densitometer uses diffuse light and your enlarger has a condenser, the results will not match. Take some readings with your lab meter and your enlarger to verify the results