This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Factors Impacting Precision of Viscosity Measurements at Low Temperature and Low Shear Stress
Technical Paper
2003-01-1385
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
There are two distinct sources of variation when making viscosity measurements of lubricating oils at low temperature and low shear stresses -- the variations attributable to the instrument and the variations from the materials being measured. Oil variation arises primarily from the ‘crystal forming’ characteristics of the fluids tested at low shear stress. In this study, the viscosities of several fluids were measured at low temperature and low shear stress using the Mini-Rotary Viscometer (MRV), which contains nine separate viscometer cells that are cooled and controlled in unison. The testing procedure was to measure the viscosities of nine samples of each oil in a single test. Data were analyzed to compare the variances and standard deviations of the normalized viscosities. The results showed that the precision of the test on PAO-type oils was better than that for fully-formulated commercial oils. Before the variation of the fluids could be evaluated, the variation of the MRV was thoroughly investigated and several improvements to the instrument were made. This study suggests that fill volume, resistance to movement, heat leakage and calibration variation all contribute to precision but when these problems are corrected, there still remains a small contribution of the material characteristics to the precision of the measurements.
Recommended Content
Authors
Citation
Alexander, D. and Henderson, K., "Factors Impacting Precision of Viscosity Measurements at Low Temperature and Low Shear Stress," SAE Technical Paper 2003-01-1385, 2003, https://doi.org/10.4271/2003-01-1385.Also In
References
- SAE J300 Engine Oil Viscosity Classification
- SAE J306 Automotive Gear Lubricant Viscosity Classification
- Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (the Calculation of Dynamic Viscosity
- Standard Test Method for Predicting the Borderline Pumping Temperature of Engine Oil
- Standard Test Method for Apparent Viscosity of Engine Oils Between -5 and -35 °C Using the Cold-Cranking Simulator
- Standard Test Method for Low-Temperature Viscosity of Lubricants Measured by Brookfield Viscometer
- Standard Test Method for Determination of Yield Stress and Apparent Viscosity of Engine Oils at Low Temperature
- Standard Test Method for Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
- Standard Test Method for Determination of Yield Stress and Apparent Viscosity of Used Engine Oils at Low Temperature
- Alexander D. L. Rein S. W. “Viscometer for Predicting Low-Temperature Pumpability of Engine Oils” SAE Technical Paper 770732
- Rhodes R. B. “Low-Temperature Compatibility of Engine Lubricants and the Risk of Engine Pumpability Failure” SAE Technical Paper 932831
- “Cold Starting and Pumpability studies in Modern Engines,”