Dielectric Thermoscopy Characterization of Water Contaminated Grease

ABSTRACT

The temperature dependence on the dielectric properties of water-contaminated grease is investigated in this article. The purpose of this investigation was to identify the dielectric properties that could be measured to differentiate varying levels of water contamination in calcium sulfonate complex (CaS-X) grease with three different test cells with the purpose of eventually developing a grease condition sensor. Measuring the change in dielectric constant over a small temperature change yielded useful estimations of water content and amount of grease where the added water content ranged from 0.22% to about 5.5%. Additionally, other parameters such as incomplete fill/coverage of the sensors were investigated as a prestudy. The results from this set of experiments show that the measurement has potential to be developed into a condition monitoring sensor in the future.

KEYWORDS:

• Condition monitoring
• water contamination
• lubricating grease

Funding

This work is partially supported by SKF–LTU University Technology Center (UTC) and the Jacob-Wallenberg Foundation. The authors gratefully acknowledge SKF and the Jacob Wallenberg Foundation for support that has made possible the initiation of this research in advanced condition monitoring techniques within LTU.