Configured for 48 chests with iron ore.
Full Red: 25% or less. Yellow: 50% and 75% Full Green: 100%
To change the item and the amount of chests just change the item in the arithmetic combiner and put 1% of the sum of all items in the chests..

Originally shared on the public FactorioPrints / Factorio School archive (factorioprints.com · factorio.school). Authorship preserved from the public catalog.
Configured for 48 chests with iron ore.
Full Red: 25% or less. Yellow: 50% and 75% Full Green: 100%
To change the item and the amount of chests just change the item in the arithmetic combiner and put 1% of the sum of all items in the chests..