Oil samples and analysis: The key to lubricant management
To ensure that the lubricant provides optimum machine functionality
and does not contain any undesirable deposits or contaminants,
regular analysis of oil samples is essential. This oil sample analysis
not only allows operators to monitor the condition of the lubricant, but
also to identify potential problems early on before they lead to expensive damage.
Normally, a fresh lubricant is clear, slightly amber to honey brown (depending on viscosity and formulation). A cloudy color or very dark oil may indicate oxidation, contamination or wear.
The viscosity analysis is used to check whether the lubricant still has the correct consistency. Oil that is too viscous can indicate thickening due to contamination or ageing, oil that is too thin can lose its protective effect.
Water in the oil can impair lubricity and lead to corrosion. A water analysis provides information on whether moisture has penetrated the system and how large the proportion is.
This figure indicates the content of acidic components in the oil. An increase in the acid number can indicate oxidation or impurities in the oil that make the lubricant more aggressive towards the machine parts.
An example of an oil sample from a gearbox or hydraulic system could be
as follows:
Color
The oil has a dark brown to black color.
Viscosity
The viscosity of the oil has changed due to oxidation, and the value is outside the recommended range.
Heavy metal content
The analysis shows an above-average amount of iron particles, which indicates wear of the gears or bearings.
Water content
An increased water content of >2% is detected, which could indicate a leak in the system.
1. sampling
First, an oil sample is taken under controlled conditions to ensure that it is representative of the entire lubricant in the system. It is important to take the sample correctly so that no external impurities falsify the result.
2. laboratory analysis
The sample is then analyzed in a specialized laboratory for various parameters, such as viscosity, metallic impurities and many others.
3. interpretation of the results
Based on the results, conclusions are drawn about the condition of the lubricant and the condition of the machine. An analysis report often contains recommendations as to what else should be checked, etc. and when the next oil analysis or lubricant change should be carried out.
4. measures
Depending on the results of the oil sample analysis, it may be necessary to replace the lubricant, clean the machine or replace components before major damage occurs.
