What are we testing with OilVue?
Tests for Oil Condition
Improper Viscosity can affect a lubricants performance. Too low of a Low viscosity will not create sufficient surface film to keep moving parts separated and prevent rubbing on opposing metal surfaces. Too high of a High viscosity will create excessive heat and reduced fluid flow within circulating systems. A change in viscosity will indicate a change in the fluid performance integrity. A drop in viscosity generally indicates contamination with a lighter product, addition of an incorrect viscosity grade, and in some cases thermal cracking. An increase in viscosity can indicate oxidation and reduced service life due to age, addition of an incorrect viscosity grade, or excessive soot or insoluble content.
Base Number represents the level of alkalinity reserve available for neutralizing acids formed during the combustion process and may be introduced through recirculated exhaust gases. As the lubricant ages and the additive package depletes, the base number will decrease from its initial fresh oil value.
Acid Number in a new lubricant represents a certain level of additive compounding. This can come from antirust, anti-wear or other additives. The acid number can drop a bit after a lubricant has been in service for a certain period, which indicates some initial additive depletion. After a time the acid number will start to increase, which indicates the creation of acidic degradation products related to oxidation. The acid number is a means of monitoring fluid remaining service life.
The Oxidation Number is a relative number that monitors increase in the overall oxidation of the lubricant by infrared spectroscopy. This test parameter generally complements other tests for fluid service life, such as viscosity and acid number. Generally, this test is not used as a primary indicator when all other tests are within normal limits. Accurate oil information is required to get the most valid test results.
The Nitration Number is a form of oxidation that relates to chemical reaction with nitrogen, forming nitrogenous compounds also. Nitration is a relative number that monitors increase in the overall fluid degradation due to reaction with nitrogen and oxygen by infrared spectroscopy. This test parameter generally complements other tests for fluid service life, such as viscosity and acid number. Accurate oil information is required to get the most valid test results. Contributors to increased nitration can come from exhaust gas blow-by or reaction with natural gas products with the lubricant and heat. It is also an indicator of electrostatic discharge across filter surfaces in turbine oil.
Tests for Lubricant Contaminants
Water as a contaminant will generally lead to increased corrosion, depletion of proper lubricating film, decreased lubricant performance life and increased acid formation.
Coolant contamination will degrade lubricant service life and performance, create sludge and block lubricant passageways.
Fuel Dilution will decrease fluids viscosity, therefore affecting its lubricity properties. Fuel dilution also promotes degradation of lubricant service life and additive properties.
Excessive Soot increases viscosity, creates excessive wear, and will tie up active additives needed for lubricant performance.
“Clean Systems” require a minimum level of cleanliness in order to operate reliably. This is especially true for circulating systems with high pressure and close tolerance components. The ISO Cleanliness Rating is a convenient way to communicate the level of particulate contamination within a system based on the Particle Count for micron sizes greater than 4, 6, and 14.
Tests for Wear Debris
Particle Quantification Index (PQI) is a valuable trending tool for monitoring the relative level of ferrous wear material within a lubricant sample.
Filter patch inspection provides a visual assessment of wear particle and other solid debris present in a sample after collection on a 0.8 micron to 5.0 micron filter membrane and examined by a microscope.
Microscopic Particle Examination (Analytical Ferrography) provides detailed information on different wear particles present in a sample. This is generally an exception test that provides information on the type of metal makeup of the wear particles present and how they were formed.