How Donaldson Oil Analysis Works

The Donaldson oil analysis service includes evaluating the results of the tests we perform and providing detailed reports, including specific maintenance recommendations. You can use our data and recommendations to improve your preventive maintenance, reduce equipment downtime, and reduce your overall cost of lubricants by extending your oil drain intervals.


There are 5 processing steps to the Donaldson oil analysis service:

1. Collect the Sample

A portion of oil is removed from a machine and sent to our lab. Sampling devices are ordered through your local Donaldson distribution outlet.

2. Complete the Sample Processing Form

For each piece of equipment to be sampled, a sample processing form must be completed. It is vitally important to inform us of any mechanical work or operating problems with the sampled system. This feedback influences our future recommendations and interpretations. Communication between you and the laboratory is essential for an effective oil analysis program.

3. Label the Sample

The label on the sampling container should always be filled out completely to assist in our correct identification and analysis of the sample.

4. Send the Sample to Lab

Always use First Class Mail, UPS, FEDEX, or other commercial delivery service for quick transport of samples. We strongly recommend you do not “hold” samples before mailing them.

5. Review the Results

The Laboratory Report

This is the heart of the program. Each computerized report indicates the results of the current and up to 5 previous samples for a given sampling point–making trending simple– plus comments and maintenance recommendations provided by trained Data Analysts.

Data Analyst Recommendations

After testing is complete, our experienced Data Analysts evaluate the results and make specific comments about the results, their significance, and recommended maintenance actions. In all cases, the final decision to follow the recommendations is yours. We have provided you with test results and recommendations, which you can use as a tool to make more accurate maintenance decisions. The effectiveness of this tool is related to the quality of the sample, the information you provide the lab, and your desire to use our ser- vice.

Glossary of Terms

The following is furnished as an aide for understanding the terminology and application of routine oil analysis as provided by Donaldson’s independent lab: Analysts, Inc.

Fuel Dilution (% by volume)

The amount of unburned fuel present in a sample of crankcase oil. High fuel dilution is generally caused by excessive idling, improper adjustment, and/or faulty components within the fuel delivery system.

Fuel Soot (% mass)

An accurate measurement of the dispersed fuel soot present. Performed by Light Extinction Measurement (LEM) and reported as % mass, soot levels are indicative of air/fuel ratios, fuel delivery and valve settings, and combustion/ exhaust efficiency. The state of the fuel soot depicts dispersant additive effectiveness.

Infrared Analysis

Organic compounds present in lubricating oils will absorb infrared light at specific frequencies. The most common frequencies measured in oil analysis indicate fuel soot, oxidation, nitration, water and glycol. Reference (new oil) samples are required for effective determination and interpretation.

• Fuel Soot is a relative measure of the

insoluble carbon present in the lubricant which is applied to evaluating combustion efficiency.

• Oxidation is the degradation of oil when molecules chemically combine with oxygen. Oxidation is part of the normal aging process which can be accelerated by increased temperature and the presence of acids. Oxidation increases viscosity and contributes to sludge and varnish deposits.

• Nitration, in the form of nitrogen oxides, is formed during the combustion process and when combined with moisture forms nitrous acid. Nitration is indicative of ring blow-by, can be corrosive, and contributes to oxidation and increased viscosity.

• Water is measured and reported as percent by volume.

• Glycol. Appraised for the presence of glycol based coolant and reported as Positive or Negative.

Water (% by volume)

The amount of water suspended in a lubricant can be detected at levels as low as 0.05% by volume. This test is performed by the hot plate “crackle” method. Water content is evaluated in conjunction with other related tests for identification (fresh, salt, coolant, etc.) as well as probable source.

Water (parts per million by weight)

The amount of water suspended in a lubricant as measured by the Karl Fischer titration method and expressed in parts per million (ppm) by weight. This method measures water levels down to 1 ppm and is generally applied to fluids from systems, which have a low water tolerance or low water requirements (refrigeration compressors, hydraulic systems, turbine oils, etc.).



The measurement of a fluid’s resistance to flow at a given temperature in relation to time. Viscosity measurements are used to determine a fluid’s classification by grade, and may indicate level of dilution, shearing, oxidation, and/or product contamination.

Neutralization Number

A number expressed in milligrams of reagent required to neutralize one gram of lubricant. The neutralization number is measured and reported as either a Total Acid Number (TAN) or Total Base Number (TBN), depending on the lubricant and application.

• Total Acid Number (TAN) is a measure of the total amount of acid products present in the lubricant. Generally, an increase in TAN above that of the new product is an indication of contamination by an acidic product or the result of oil oxidation.

• Total Base Number (TBN) is a measure of the alkalinity remaining in a lubricant. A relatively low TBN, or a decrease in TBN compared to the new product, indicates low acid neutralizing characteristics or a depleted additive package.

Particle Count


A numerical count of particles present in a lubricant, which are measured within specific particle size ranges. This test is generally associated with fluids, which require the controlled filtration of particles 50 microns or less in size (e.g. hydraulic systems).

Spectrochemical Analysis

Selected metallic elements present in the form of microscopic particles are identified and reported as parts per million (ppm) by weight on an atomic emission spectrometer. These elements provide the means for monitoring wear elements, corrosion, debris, airborne contaminants, coolant additives, and metallic oil additives. Interpretation of results should be made by a trained and qualified Data Analyst.

Wear Particles

The source of these elements, either individually or in combination, as in an alloy, will vary with the manufacturer and type of system analyzed. Wear analysis is most effectively applied when a series of samples from a component are evaluated on a routine basis for “trend analysis.”

Airborne Contaminants

Silicon, present as silica dioxide (sand) is the most common and dominant element within airborne contaminants. New oil reference samples are required for effective evaluations since silicon may also be present due to oil or coolant additives, sealants, and/or other sources.

Coolant Indicators

Antifreezes and coolants are formulated with many different combinations of additives and inhibitors. In the event of a coolant leak, these trace elements will remain present in the lubricant even when the water has been evaporated by operating temperatures. Coolant reference samples are required to identify each specific formulation.

Metallic Additives

Lubricating oils are formulated with many different types of “additive packages” to fulfill the operational requirements of equipment and the manufacturer’s specifications. These packages may include metallic compounds such as anti-oxidants, anti- foaming agents, dispersants, detergents, and/or solid film lubricants.

For more information on Donaldson’s Oil Analysis program visit:

T he article appeared in the June 2012 issues of the Associate Construction Publications magazines national section.


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