An In-Line Method for Measuring Oxidation in Gear Oils and Hydraulic Fluids

A study was conducted to examine degradation of a gear oil and a hydraulic fluid using an in-line polymeric bead matrix (PBM) system that correlates oil oxidation with a relative change in the solvent properties of a fluid. The solvent property is an inherent aspect of an oil and allows oxidation to be measured independent of the base type, additive package, and viscosity. Samples of gear oil were heated to simulate a typical oxidized condition. Hydraulic fluids from a turbine were run for a limited time to provide discrete oxidized samples and test the sensitivity of the method. Results for the gear oils with the PBM are shown to compare favorably with infrared (IR) spectroscopy at room temperature. Elevated temperatures available with the PBM were needed to resolve oxidation levels for the hydraulic fluids.

Presented at the ASME/STLE Tribology Conference in Long Beach, California October 24-27, 2004

Review led by Bob Errichello

KEYWORDS:

• Oxidation
• Additive Depletion
• Gear Oil
• Hydraulic Fluids
• Condition Monitoring

ACKNOWLEDGEMENTS

We wish to express our thanks to Herguth Laboratories at 101 Corporate Place, Vallejo, CA, for their help in providing us representative oil samples, comparative analysis, and many helpful discussions.

Notes

Presented at the ASME/STLE Tribology Conference in Long Beach, California October 24-27, 2004

Review led by Bob Errichello