Evaporation loss according to Noack

Test instrument: microscope
Sample quantity: 150 ml
Unit: %
Analysis for: engine oils, circulating oils
Brief description: The sample is weighed out into a crucible which is heated to 250 °C for 60 minutes. A constant flow of air is drawn through the crucible and the decrease in sample quantity is measured.

Lubricating oils, especially mineral oil-based products, are usually multi-component mixtures. This means, among other things, that these products do not have a boiling point, but a boiling range that is very wide in some cases. How wide the boiling range is is essentially influenced by the fractions from which the base oil has been produced. Pre-dissolved additives also have an influence on the evaporation behaviour of a lubricant.

The evaporation loss according to Noack differentiates lubricating oils according to their evaporation behaviour and ultimately also the oil consumption in the application. However, it must be taken into account that other factors can also influence the oil consumption in the respective application.

The determination of the evaporation loss according to Noack is also required in some lubricant specifications, e.g. ACE or API for engine oils.

Underlying test standard: DIN 51581-1