Someone correct me if I'm wrong. but, isn't a TBN number of 7.0 considered a neutral ph? Any number below this is acidic and above 7.0 is alkyline?
[ November 21, 2002, 09:02 AM: Message edited by: westex39 ]
No. ph is a log scale 0-14. And yes on this scale 7 is what we call nuetral. I won't get into "free" H+'s or -OH's or Lewis....but for shortening the discussion at pH 7 the "system" has a balance.
TBN=Total Base Number. Not a "scale" (log or not) is basically a measure of remaining "basic" agent or starting "base" that will/should nuetralize any acid/acid products formed. A low number does not mean the oil has gone "acid" (low pH) just that the base is being depleted. Most useful when you compare with what the starting TBN was. Measured by titrating, and expressed in terms of the equivalent number of milligrams of KOH.
[ November 21, 2002, 09:41 AM: Message edited by: Pablo ]
I was recalling my chemistry days whan 7.0 was neutral. I can see what you are talking about with the scale of 0 - 14. If you ever had a 0 reading you would be completely depleted as far as neutralizing any more acid that formed.