The Titra-Lube laboratory method is run as follows:
A sample of the lubricant to be tested is weighed out into a disposable test tube. The amount of sample used in grams is determined by dividing 16 by the expected TBN value of the sample. The maximum amount of sample to be used is 2 grams.
The tube is filled to a 5 mL line with a high flash point hydrocarbon based solvent and the tube is capped and shaken until the sample is totally dissolved.
3.1.5 mL of 0.40 M isopropyl HCl is added to the tube and it is shaken for 30 seconds.
12 mL of aqueous extract solution is added and the mixture shaken for 30 seconds.
The two phases are allowed to separate for 3 minutes.
The aqueous layer is decanted off and 10 mL is transferred to a titration beaker.
12 mL of additional aqueous extract solution (clean) is added to the beaker and the solution is titrated with 0.0425 N NaOH to the inflection point. The titration can be done manually or with an automatic titrator.
TBN is calculated as follows:
TBN = 3.20 (Vb1-V5)/Ws, where Vb1 is the amount of titrant used to titrate a 0 TBN blank sample, Vs is the volume of titrant needed to titrate the sample being analyzed, and Ws is the weight of the sample used in the procedure.