Guys .
1.What ia the best way to find out and analyzed TBN & TAN in engine oil ,meanwhile we do not have the original data from the oi suplier?

Take a sample from a new drum, have it analysed (to include the parameters you want to monitor) and use this data as your reference/baseline

Auliadj,

TBN or Total Base Number, is a measure of the reserve alkalinity of the oil. Internal combustion engines include this as an additive, and the amount in a new oil can vary widely. Some diesel engine oils have a new TBN of 8-12, and some marine diesels may be as high as 30. It is important to know the new oil formulation to be able to tell just how much has been consumed by neutralizing combustion blowby gasses. Sometimes the manufacturer will provide that info, but I agree with Buzz that it is best to sample the new oil coming in, and analyze that. That does two things-first, it allows you to QC the incoming oil (for things like cleanliness-particle count, proper viscosity, etc) and also to baseline the TBN.
Some will then condemn the TBN at half the original value, or perhaps when it reaches 2 mgKOH/gOil. The 1/2 original value is perhaps a little conservative, especially for highly additized oils, and the 2mg is possibly a little low and directs action a little late. Trending the value is the most important thing, and any sudden changes in the trend as a function of run hours should be carefully looked at as an indication of problems.
TAN can also be baselined with the new oil drum. Condemning limit there is typically an increase of 0.3 mgKOH/gOil. Hope that helps.

Rich Wurzbach
CLS, OMA, LLA-I
MRG Power Labs
York, Pennsylvania

If your interested in having a versitile on-site portable tool for this, check the RULER:
http://www.reliabilitydirect.com/oilanalysisproducts/FLU-Ruler.htm

DavidG, can RULER monitor all these parameters?

1) Goal based limits
Parameter: Caution to Critical
Cleanliness 14/11 16/13
Wtr content 0.3% 0.5%
TAN 0.2 0.4
Fuel 1.5% 5%
Glycol 200ppm 400ppm
Soot 2% 5%
Flash point Drop of 30o Drop of 50o

2) Ageing limits
Parameter: Caution to Critical
Viscosity +/- 5% +/- 10%
RBOT -30% -60%
FTIR-Ox 0.3 1.0
Zinc -15% -20%
Calcium -10% -20%
TBN -50% -75%

Josh,

While the RULER is a very good tool for managing the oxidative life of an oil, and testing incoming oils for concentrations of anti-oxidant additives, it does not address most of the criteria you list. Your list includes Ageing Limits, however it does not monitor the concentration of anti-oxidant additives in the tests you list there. Instead, it relies on FTIR-Ox and TAN to see progression of oxidation after the anti-oxidant additives have been essentially completed. There is also RBOT, which is a proactive test that can often see the depletion of the anti-oxidant additives. Depending on the justification for your list, it is possible to substitute RULER for RBOT at a much lower cost. Many facilities are doing this. RBOT, or RPVOT as it is currently called, also looks at other proactive parameters such as the accumulation of free radicals, but has been shown to have a non-linear relationship to oxidation potential, and is not always a reliable predictor of remaining life from that perspective.
The RULER equipment also has TAN capabilities, but I'm not sure that there is an ASNT test protocol for that.
So, while RULER is very effective and an important tool in managing the remaining useful oxidative life of a lubricant, it is not a substitute for a carefully constructed test slate that addresses wear, contamination, and physical properties of the oil, as well as addressing the goal and ageing limits that are a part of an effective lubricant and machinery monitoring program.

Rich Wurzbach
rwurzbach@mrgcorp.com
MRG Power Labs

Rich, thanks for your comments. Can "Adopting online oil analysis with SmartSkidTM" replace the periodic offline oil analysis at Lab for all those parameters cited above?