Acid Number Tester (ASTM D664)
Introduction:
The base value of lubricating oil represents the standard for the content of alkaline substances in lubricating oil. It is an indicator of the effective additive composition in the oil to indicate the neutralization capacity of the lubricating oil.
For diesel engine lubricating oil, the base value is because diesel engines, especially ships, burn sulfur containing heavy oil and other fuel oil, and this kind of diesel oil is mixed with fuel oil in the engine, resulting in the engine will produce acidic substances during operation, so the significance of the base value here is to neutralize acidic substances and prevent equipment corrosion.
Base value is an indicator of the content of alkaline substances in lubricating oil, and the unit is mgKOH/g.
Why test total acid number / base number?
1. According to the size of the acid value, the amount of acidic substances contained in the oil can be judged.
2. Oil in operation due to the influence of oxygen, temperature and other conditions, to gradually oxidize and produce a series of oxidation products, of which the most harmful is acidic substances, mainly naphthenic acid, hydroxyl acid and so on. The higher the acid value of the oil in operation, the deeper the aging degree of the oil, so the acid value is one of the main control indexes of the aging degree of the oil in operation.
3. Insulating oil contains all kinds of acidic substances, which will improve the electrical conductivity of the oil and reduce the insulation performance of the oil. When the low molecular acid content is increased and there is water in the oil, the insulation level of the electrical equipment will be reduced and the operating life of the equipment will be shortened.
4. The increase of the oil acid value of the steam turbine in operation indicates that the oil has been deeply aging, and the naphthenic acid soap formed in the oil can promote the emulsification of the oil, destroy the lubrication performance of the oil, cause wear and heating of the parts, and affect the safe operation of the unit.
| 1 |
Measuring range |
>0.01mgKOH/g |
| 2 |
Accuracy |
relative error ≤5% |
| 3 |
Potential measuring range |
0 ~ ±1999.5mv |
| 4 |
Basic error |
±0.1%F.S ±0.5mv |
| 5 |
Burette volume |
10ml |
| 6 |
Small volume of burette |
0.01ml |
| 7 |
Burette accuracy |
±0.1%F·S |
| 8 |
Full set |
host, titration unit, computer (including the operating software), printer, etc. |
Executive Standard:
GB/T264 Standard Test Method for Acid Number of Petroleum Products.
GB7599-87 Determination of acid number in transformer and
turbine oils in service
GB/T7304-2000 Petroleum products and lubricants--Determination of acid number
GB/T 18609-2001 Determination of crude acid value by potentiometric titration.
ASTM D664-2011 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
Audited Supplier 
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