If you asked Canadian petroleum chemist J.S. Charlesworth in 1947 what the most important characteristic of lubricating oil was, he would have said, Viscosity1. After all, he said, “it’s a measure of the oil’s resistance to flow, or of its internal friction…[i]t indicates…the ability of an oil to support loads.” At just about the mid-20th century, the American Society of Testing and Materials (ASTM) published a set of standards for the measurement of viscosity of petroleum products2. Of course, the importance of viscosity is well known today, and there are standard methods worldwide to ensure uniformity of testing.
But if you know your oil’s initial viscosity and its suitability to your application, why should you test it regularly? Viscosity, while a fundamental characteristic, is also changeable, depending on certain environmental conditions. Temperature fluctuations, especially excessive heat, moisture, exposure to air, all can impact viscosity. So the oil/lubricator you have in front of you may not exactly match the viscosity level you need in order for the material to perform correctly under your specific real-world conditions.
In an article published on ASTM Standardization News more than 15 years ago, authors Janet L. Lane and Kenneth O. Henderson made a stunning argument for testing viscosity in petroleum products. They say, “In economic terms, an error of 1 percent product viscosity that causes a blend adjustment can easily result in increased product cost by a penny a gallon. For a large lubricant manufacturer, this can amount to $1,000,000 in lost revenue per year.”3 The cost is certainly no less today. Fortunately, it’s a risk you don’t have to take.
Today, viscosity analysis is a precise, yet simple, and highly effective process. Compliance with standard methods, appropriate sampling, and calibration integrity is critical.
LGC has significantly expanded our portfolio of viscosity standards through the recent acquisition of Paragon Scientific. Our viscosity-certified reference materials are certified in accordance with international test method protocols such as ASTM, EN, or IP and are fully traceable to international standards. You can find our full range of these reference materials in our catalog and our team is ready to address any questions you may have!
- THE SIGNIFICANCE OF GENERAL LABORATORY TESTS ON FUELS AND LUBRICANTS By J.S. Charlesworth Chemist Gasoline and Oil Testing Laboratory Research Council of Alberta University of Alberta Edmonton, Alberta 1947
- Viscosity Measurements for Petroleum Products, Clifford Jones on behalf of University of Aberdeen, Petro Industry News, May 2013 (www.petro-online.com/article/analystical-instrumentation/11/university-of-aberdeen/viscosity-measurementsnbspfor-petroleum-products-nbsp/1417)
- Viscosity Measurement – So Easy, Yet So Difficult, Janet L. Lane and Kenneth O. Henderson, ASTM Standardization News (https://www.astm.org/SNEWS/JUNE_2004/lanhen_jun04.html)