Originally Posted By: m37charlie
1ppm Mg has the same molarity as 1.67ppm Ca; the atomic weight of Mg is 24, Ca 40. PPMs are by weight. They are both divalent cation alkaline earth metals
Charlie
I've read a lot of your post with great interest for the past few months, so now I must ask, what do you do for a living. Are you a chemist or tribologist?