"The potency of medications that the G4 looks at is from IV bags and syringes. It is an obvious no brainer that vials cannot be treated the same " Pennstreet, for us simpleltons, why can't the iG4 read the concentration of a drug from a vial, yet allegedly can read it from an IV bag or syringe. This is the third time that I've asked for an explanation to your obvious "NO BRAINER".