Oil Analysis

Oil Analysis

What is Oil Analysis?

The analysis of oil samples from plant machinery such as gearboxes, engines, compressors etc can reveal information regarding the condition of the machine's internal components.

Oil Analysis

The results of Oil Analysis can determine component wear, bearing wear, additive depletion / fuel dilution, coolant leaks, contamination, ingress of dirt, deterioration of internal seals etc.

When Oil Analysis is used as part of a proactive maintenance regime, such as Condition Monitoring and Condition-Based Maintenance, the results of oil samples taken from the same machines over a period of time can be trended to gain an insight into the machine's operating condition. Any changes in the machine's condition, such as the onset of internal component wear, can then be quickly identified and a time to failure can be estimated, thereby enabling Maintenance Technicians to make informed decisions on corrective repairs.

Monition Ltd operate one of the UK's largest independent Oil Analysis Laboratories, and provide a comprehensive suite of Oil Analysis services for used-oil samples.

Benefits of Oil Analysis

Oil Analysis is the most cost-effective approach available to prevent machine breakdowns and reduce lubrication and maintenance costs, enabling you to:

  • Maximise oil lifetime by only replacing lubricants when necessary
  • Prevent breakdowns by early identification of deteriorating machine components
  • Schedule planned downtime to maintain machines
  • Reduce lubrication and maintenance expense
  • Reduce environmental impact by reducing waste oils
  • Manage their machinery lubrication programmes effectively

Industrial Applications for Oil Analysis

Understanding the condition of lubricants in industrial machines and systems such as gearboxes, pumps, motors, engines etc, is a key consideration within the field of Predictive Maintenance.

When a lubricant is analysed, as well as discovering the condition of the lubricant in terms of its performance, chemical integrity and performance of any additive packages, the lubricant will also reveal the condition of the internal components within a mechanical system. When components such as gears, bearings and tappets begin to wear-out, microscopic metal wear particles are released into the oil as it circulates throughout the machine's system.

Oil Analysis identifies the type and amount of these wear particles, and can pinpoint the exact component which is beginning to break down.

Furthermore, by trending the result of oil sample analysis taken from the same machines over a period of time, and monitoring the levels of ferrous wear particles contained within the oil samples, oil analysis can offer an accurate prediction of remaining life expectancy for internal components - without the machine having to be dismantled and inspected.

Oil Analysis is therefore a vital component in a Condition-Based monitoring and maintenance program, as it enables Maintenance engineers to understand the condition of their plant at any given point, and to schedule and conduct remedial repairs as required.

Not only can Oil Analysis verify when a lubricant or component requires replacement; oil analysis can also confirm when a machine or lubricant is in satisfactory condition. Therefore, where an oil manufacturer's recommendations may be to replace a lubricant, for example, every 5,000 hours of use, oil analysis at this point may indicate that the oil is in perfectly operable condition, and therefore enable to oil to remain in the machine, with confidence, for an extended period, saving the expense of time and replacement.

Oil Analysis Laboratory Tests

ICP AES (Inductively Coupled Plasma, Atomic Emission Spectroscopy)

Analysis of: wear metals, additives and contaminants. ICP gives the elemental analysis of the oil. The ICP can analyse for elements in solution at <10 microns in size. Common elements analysed for include - Iron, Calcium, Aluminium & Silicon.

Viscosity (Kinematic viscosity at 40°C and/or 100°C)

Viscosity of the oil gives an indication as to the correct grade of oil in use, Oxidation/Overheating, Fuel dilution and oil mixes.

PQ & FW (Ferrous Wear Index)

The ICP elemental analysis can only analyse particles in solution <10 microns in size. The Ferrous Wear Index gives an indication of the total measure of Iron (regardless of size) in the sample. This technique is used to determine early component wear.


Water and oil do not mix, which is why testing for water can give information on possible water ingress, oil cooler and engine coolant leaks. Oil saturated with water produces an emulsion, which cause corrosion which affects the load bearing capacity and reduces lubrication properties.

TIM (Total Insoluble Matter) (A measure of Soot and oxidation products)

TIM is a test used for engine oils. The basis of the test is to measure the optical density of the oil (how dark it has become). The results can give an indication of Poor combustion, inefficient/old air and oil filters and also shows the ability to support the insoluble material in suspension (dispersion).


A Dielectric analysis of the oil can give the following information:

  • Chemical index (measure of water, Oxidation, Soot, Acids, different oil to specified grade)
  • Contamination Index (the level of oil insoluble contaminants such as, water, coolant, wear particles)
  • Large Ferrous and non-Ferrous debris
  • The Oil life Index (the measure of deterioration of the lubricant over time)
  • TAN (Total Acid Number)

TAN is generally carried out as required on Gearbox and Hydraulic oils. The test is a measure of the acidity of the oil. When a known oil is in use the results of the new and used oil can be compared, this can indicate possible oxidation, additive and oil degradation. The TAN value in conjunction with other tests can give greater insight into the condition of the oil.

TBN (Total Base Number)

TBN is carried out as required on engine oils. The TBN value when compared to the new oil value can indicate the life of the oils base reserves. The alkalinity of the oil allows for acidic oxidation by-products of the combustion process to be absorbed with no significant lubrication or corrosive effects. As with TAN, the TBN value in conjunction with other tests can give greater insight into the condition of the oil.

Particle Size Distribution (Cleanliness of hydraulic systems to ISO 4406)

Particle count is a measure and size breakdown of the solid material content in oil (usually hydraulic systems). The count can give an indication of abnormal wear, effectiveness of filters and filtration, dirt ingress and breakdown of seals.

Oil Analysis Services

Monition's fully-independent Laboratory offers Oil Analysis Services to customers across the world.

Detailed Lubricant Analysis is combined with clear, easy-to-understand Reporting to enable customers to understand the results of analysis and the actions that are required to help maintain the reliability of plant and machines. Monition is an Achilles Link-Up approved service-provider to the rail industry.

Monition's ISO 9001:2000 accredited service includes:

  • Supply of Oil sampling kits
  • FREEPOST return envelopes (UK only)
  • Screening of Samples on arrival at Lab
  • Detailed Oil Analysis
  • Reports emailed directly to customers
  • Online Reporting facilities available

ICP AES Oil Analysis

ICP AES (Inductively coupled plasma atomic emission spectroscopy) is the standard technique used in labs to determine the wear metals, additives and contaminants of an oil.

The initial set up of an ICP method is to determine the correct wavelengths (in Nanometres) for the elements of interest. If we give the example of a conventional digital camera, if an unsuitable line is selected for Iron, this may be because there is high sensitivity and therefore a small amount of Iron will overexpose the resulting image. Alternatively a line of poor sensitivity will not detect low level. Lines are selected through trial and error with the expected range of concentrations in mind.

When the method has been designed a calibration is carried out. The calibration uses Organo-metallic standards, which contain known levels of elements in parts per million (1ppm = 0.0001%). For a simple calibration of Iron you could select three standards, 0 ppm, 100ppm, 1000ppm. At this stage you are again checking the suitability of the line selected. Across your desired level range the resulting calibration curve should be more or less linear.

For sample analysis, the oil sample is diluted with Kerosene or White spirit to a ratio of 1:10. This dilution allows for the viscous oil to be drawn through fine Teflon capillary tubing into the ICP for analysis.

The sample is then injected into a nebuliser which mixes the sample with a flow of Argon. This is then carried into the spray chamber which literally creates a mist of the sample. A small percentage of this sample is then drawn up into the torch and Argon Plasma for analysis.

The ICP torch consists of 3 concentric quartz glass tubes which is water cooled by a copper coil.

"When the torch is turned on, an intense magnetic field from the RF generator is turned on. The argon gas flowing through is ignited with a Tesla unit (typically a copper igniter on the outside of the tube). The argon gas is ionized in this field and flows in a particular rotationally symmetrically pattern towards the magnetic field of the RF coil. A stable, high temperature plasma of about 6500°C is then generated as the result of the inelastic collisions created between the neutral argon atoms and the charged particles.

The sample immediately collides with the electrons and other charged ions in the plasma and is broken down into charged ions. The various molecules break up into their respective atoms which then lose electrons and recombine repeatedly in the plasma, giving off the characteristic wavelengths of the elements involved.

Optical lenses or Fibre optics are then used to focus the emitted light on a diffraction grating where it is separated into its wavelength. The light intensity is then measured with a photomultiplier tube or CCD camera and chip at the specific wavelength for each element line involved.

The intensity of each line is then compared to previous measured intensities of known calibrations of the element and its concentration is then computed by extrapolation along the calibration line.

Further Information regarding Oil Analysis

Monition can provide assistance in all your Oil Analysis applications. For further information on Oil Analysis or arrange onsite alignment of plant machinery, please telephone Monition on 01909 722000. Alternatively you can email us at enquiries@monition.com or complete our enquiry form and one of our sales team will contact you to discuss your requirements.

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Tel: 01909 722000 | Email:enquiries@monition.com | Company Number: 02218477