Lubricating Oil Test Description
A technique that separates and arranges according to size, ferrous wear particles from a lubricant for analysis with a microscope. The Ferrogram provides information for the identification of wear particle types and a description of the wear mode that generates the particles.
Ash (ASTM D482)
This method determines the ash content of petroleum products as mass %. The ash content refers to the undesirable impurities or contaminants in the petroleum product. This may be used to determine if the product is suitable for use in a given application.
Cloud Point (ASTM D2500)
The cloud point defines the temperature at which wax crystals appear in the fuel upon cooling. The cloud point of a fuel and its impact on cold flow properties should be monitored to ensure trouble-free operation in cold climates.
Colour (ASTM D1500)
Using an ASTM Colour Scale as a reference, this method determines the colour of an oil sample. The colour is useful for trending to determine if any contamination with another product or degradation of the oil has occurred.
Copper Strip Corrosion (ASTM D130)
Using ASTM Copper Strip Corrosion Standards, this method covers the detection of the corrosiveness of fuels and oils to copper. The test is designed to assess the relative degree of corrosivity of a petroleum product.
This is a simple test to detect and roughly quantify (detection limit greater than 500 ppm or 0.05%) the presence of free and emulsified water that is suspended in the oil. Water in lubricating oils is a primary contaminant that leads to degradation of lubricant base-stock and additives, corrodes component surfaces, and accelerates wear due to reduced fluid film strength.
Direct Read Ferrography
This technique is an automated version of analytical ferrography. It differentiates between large and small ferrous particles and calculates the Wear Particle Concentration and the Percentage of Large Particles, both of which can be used for trending purposes.
Flash and Fire Point - Cleveland Open Cup (ASTM D92)
The primary use of this method is for viscous materials (excluding fuels) having flash points of 79C and above. This test determines the temperature at which the oil will form a flammable mixture with air. The flash point can be compared with standard specifications to determine if the oil meets the specification. It is often used as an indicator of fuel dilution. The fire point is a measure of the tendency for the oil to support combustion.
Flash Point - Pensky-Martens Closed Cup (ASTM D93)
The primary use of this method is for petroleum products having flash points as low as 40C and is applicable to fuels. This test determines the temperature at which the oil will form a flammable mixture with air. The flash point can be compared with standard specifications to determine if the oil meets the specification. It is often used as an indicator of fuel dilution.
Foaming Characteristics (ASTM D892)
This technique determines the foaming characteristics of lubricating oil. Both foam creation as well as foam collapsing characteristics is determined at several temperatures. The foaming tendencies of oil can be a serious problem in some machinery which could lead to mechanical failure.
Freeze Point (ASTM D3321)
This method tests for the approximate freezing protection provided by ethylene and propylene glycol-based coolant solutions. The freezing point is a concentration-related value directly related to refractive index. Therefore, the concentration of glycol can also be approximated.
FTIR Spectroscopy - Fourier Transform Infrared Analysis
FTIR analysis provides information on the state of the oil and the machinery from which it comes. Indicators of chemical degradation include oxidation, nitration, sulfation, ester breakdown and antiwear additive depletion. Indicators of contamination include soot, water and glycol, and fuel dilution. This technique is an excellent trending tool.
Glycol in Oil (ASTM D2982 Procedure B)
This test is a qualitative determination of glycol-base antifreeze in used lubricating oils. Leakage of glycol-base antifreeze into the crankcase interferes with the oils ability to lubricate and promotes sludge, varnishing and oxidation leading to engine malfunction and possible failure.
Heat of Combustion (ASTM D4809)
The heat of combustion is a measure of the energy available from a fuel. Knowledge of this value is essential when considering the thermal efficiency of equipment for producing either power or heat.
ISO Particle Count (IS0 4406, NAS 1638)
A method used to count and classify particles in an oil or fuel according to size ranges as specified by ISO. Based on the particles per size range, a cleanliness code is assigned to the fluid which can be compared to equipment specifications. It can determine the efficiency of filters as well as identify when abnormalities are occurring.
Oxidation by RPVOT (ASTM D2272)
This test method utilizes an oxygen-pressured vessel to evaluate the oxidation stability of new and in-service turbine oils in the presence of water and a copper catalyst at 150C. It is used for specification of new oil and can be used to assess the remaining oxidation test life of in-service oils.
pH (ASTM D1287)
The pH is a measure of the hydrogen ion concentration and indicates whether the sample being tested is acidic, alkaline, or neutral. Engine coolants should have an alkaline pH. For fire resistant hydraulic fluids, the pH is an indication of the proper ratio of water and glycol in the mixture.
Pour Point (ASTM D97)
This test determines the lowest temperature at which movement of the fuel is observed. The pour point of a petroleum product is an index of the lowest temperature of use for certain applications.
Specific Gravity (ASTM D1298)
A physical test which is used to determine the density of oil. It is an important quality indicator to determine whether the correct oil is being used or whether some degradation has occurred.
Spectrometric - Metal Analysis – Dissolved Metals ICP-AES (ASTM D5185)
A technique used to analyze metals in oil resulting from wear, contamination and additives. Only the dissolved and very small particulate forms of the metals in the oil are detected and analyzed. The concentrations of wear metals can be indicative of abnormal wear. The concentrations of additive metals may indicate depletion of the additives or the use of incorrect oil. Contamination metals from coolants or the environment will also be detected.
Spectrometric - Total Metal Analysis – ICP-AES (ASTM D5185 modified)
A technique used to analyze metals in oil resulting from wear. The conventional ICP-OES method is not capable of detecting larger metal particles which are key indicators of abnormal wear. This method includes an acid digestion step which converts these particles to a dissolved form which is then analyzed.
Total Acid Number – TAN (ASTM D644)
This method determines the amount of acidity in a lubricant. New and used oils may contain acidic compounds which are present as additives or as degradation products. The acid number is used to track the oxidative degradation of oil in service. Oil changes are indicated when the acid number reaches a predetermined level for a given lubricant and application. A sudden increase in the acid number may be indicative of abnormal operating conditions.
Total Base Number – TBN (ASTM D4739)
A method that determines the reserve alkalinity of a lubricant. The base number is an indicator of the oil to neutralize acidic compounds formed by oxidation processes. Oil changes are indicated when the base number reaches a predetermined level for a given lubricant and application.
Viscosity @ 40C and 100C - Kinematic (ASTM D445)
This method measures an oil’s resistance to flow at a specific temperature (40 or 100 C). Viscosity is one of the most important properties of a lubricant as it determines both the film thickness of the oil and how readily the lubricant will flow into the narrow area separating the moving metal parts.
Viscosity Index - Kinematic (D 2270)
This index is used as a measure of the variation in kinematic viscosity due to changes in the temperature of an oil lubricant between 40 and 100 C. A higher viscosity index indicates a smaller decrease in kinematic viscosity with increasing temperature of the oil lubricant. Changes in viscosity index may indicate a degradation of oil, contamination or the use of the wrong oil.
Water & Sediment (ASTM D 2709)
This method determines the volumetric percent of water and sediment in middle distillate fuels. Water and sediment in a fuel oil can cause fouling of the fuel-handling facilities, obstruct fuel flow and cause internal corrosion.
Water Content - KF (ASTM D6304 Procedure C)
A method that extracts water from an oil sample and determines the amount of water using a KF titration. Excessive water in the oil destroys the lubricant’s ability to separate moving parts, allowing severe wear to occur. In addition water affects corrosion rates, oil degradation resulting in loss of lubrication and premature plugging of filters, minimizing the effect of additives, and supporting the growth of bacteria.
Water Separability (ASTM D1401)
This test method determines the water separation characteristics of oils subjected to water contamination and turbulence. It is used for specification of new oil and for monitoring oil that is in service.