abs units

[widman]

Someone just gave me some results to review and the lab used "abs units" for the soot level, oxidation, and nitration.

Everything I've done for years has been in %. Does anyone know how to convert these units to %?
Example
-Soot = 79 abs
-Oxidation = 11 abs
-Nitration = 8 abs

Another one has
-Soot = 45 abs
-Oxidation = 11 abs
-Nitration = 27 abs

and another
-Soot = 139 abs
-Oxidation = 38 abs
-Nitration = 46 abs

the last two are from CAT SOS labs

 

[Pablo]

abs = absolute

Can't exactly convert to %.

 

[widman]

This what I get from Wikipedia

"Although absorbance does not have true units, it is quite often reported in "Absorbance Units"'

 

[Pablo]

That is a possibility. Perhaps ask the lab. I guess what I always think (and write) when I see % or abs, it doesn't mean much of anything unless you compare it to the same oil new.

 

[widman]

I've found these references too, but need to understand them and compare to 4000 results with %


"Soot: (Diesel Engines Only); measured in absorbance units, is a normal combustion by-product of diesel fuel and appears as a contaminant in the oil causing an increase in the oil's viscosity (thickening of the oil). Higher than normal readings can indicate an improper air/fuel ratio, defective air intakes, faulty injectors or blow-by. Soot can cause deposits, oxidation, and can also degrade oil additives. The accuracy range of this test is +/- .2 to .3 absorbance units."

"Oxidation: measured in absorbance units, is the result of oxygen in the air reacting with the oil at elevated temperatures, and is a normal process at the oil ages. If an engine is operated continuously at high temperatures for extended periods, or if a drain interval is over extended then values great than 25 may be observed and an oil change is normally recommended. This test is accurate within +/- 4 absorption units. "

 

[Pablo]

What is the source for those quotes?

 

[widman]

http://www.statelinemarinesurveyors.com/oil.html

 

[jldcol]

What are abs units? 6 packs I think those drunk and displayed internally and those trained and display externally. Yust kiddeen. Are these dimensionless numbers?

 

[Steve S]

Originally Posted By: jldcol
What are abs units? 6 packs I think those drunk and displayed internally and those trained and display externally. Yust kiddeen. Are these dimensionless numbers?
Got to be Metric