Oil analysis
TLT Sounding Board September 2026
Executive Summary
Only a third of TLT readers report that they or their customers currently use grease analysis, with sampling difficulty as the barrier cited most consistently across responses. Readers point to tools like Fourier transform infrared spectroscopy (FTIR), ferrography and ultrasound-assisted techniques as strong candidates for wider adoption, while options such as optical grease sensors and rheometry remain niche. Looking ahead, readers see the greatest need for development in real-time, onsite analysis and artificial intelligence (AI)-assisted diagnostics.
Q.1. What do you think are the main barriers to end-users adopting grease analysis?
Ease of pulling a sample is not the same as for oils, and cost to test can be higher than oils testing.
Knowledge of how to pull an adequate sample for testing.
No. 1 problem is securing a representative sample. I don't believe the industry has proven the efficacy of grease analysis, at least on a wide enough basis to expect there to be wide acceptance.
Sample collection logistics within the plant.
Probably sampling.
In my country, the lack of laboratories that carry out this type of analysis, as well as the lack of technical training on the importance of grease analysis.
Sampling, modern automatic grease testing equipment with smaller footprint.
Practicality: obtaining a representative in-use sample, and lack of corrective actions.
Consistent sampling.
Realizing the importance of maintaining the performance and quality grease and the role testing plays. I think most end-users assume as long as some grease is there, it's fine.
Availability of testing.
A lot of technicians only have a routine to apply the grease in the machinery.
Cost and convenience.
In my experience the main barriers are a lack of knowledge about grease analysis, the information they can obtain from a grease analysis to help them make decisions and the potential savings they can achieve in their tribological systems by applying tribology to those systems.
Lack of education of the importance of oil analysis. Lack of standard procedures.
Sample collection, trending ability (sample frequency), result interpretation and actions (always high dirt and wear metals detected).
Fill for life viewpoint.
Unavailability of test setups and state-of-the-art facilities.
Test bench cost compared to usage occurrences.
Lack of understanding about how grease works.
Difficulty obtaining samples and availability of good testing labs.
The difficulty of obtaining samples uncontaminated by the exterior environment complicates any such program. False positives are a high probability without careful design and preparation to allow collection of clean samples, which is not intrinsic to most existing designs/systems that I'm familiar with. Additionally, grease failures can be less obvious than in oil services, impairing buy-in from management, maintenance and operations personnel.
Lack or insufficient awareness/knowledge in this subject matter.
Availability of good labs (capabilities and experience).
Lack of knowledge does exist for greases.
Getting suitable samples consistently for analysis.
These aren't barriers; what exists is a complete lack of understanding about the benefits of monitoring lubricants to anticipate and correct failures before they become too serious. In the case of lubricating greases, the end customer, in their cost analysis, prefers to replace the grease rather than assess its condition, as it's cheaper.
1.) No appreciation of the benefits of grease analysis. 2.) Poor understanding of grease lubrication.
Much harder to analyze grease than oil.
Education as to why they need to test grease, how to collect a clean sample and knowledge as to why the grease they are using is the correct product for the application.
Minimum information in open source in terms of procedures of determination of greasing testing.
Extraction methods.
Time to do it, cost and reliable test methods.
The biggest barriers are the lack of standardized testing methods, difficulty in obtaining representative grease samples, limited trending databases and the perception that grease analysis is more expensive and less actionable than oil analysis.
Cost is the main reason, and second would be awareness.
Difficulty in obtaining samples.
Sampling.
Small and medium industries tend to apply breakdown maintenance policy.
It is very messy and needs a lot of "clean up."
Sampling equipment, training, ease of shipping and turnaround time.
Understanding the benefits.
From the viewpoint of molecular theory, the highly complex structure of grease makes it challenging to understand its fundamental properties, particularly its dynamic behavior.
Cost and lack of expertise.
Samples collection, sending samples to test lab and the lead time for the analysis report to be generated.
It is not easy to obtain representative samples.
There are a couple of reasons. 1.) Normally quantity of grease used in many applications is small so customers don't think that it is worth spending money to do grease analysis. 2.) Taking a grease sample is more difficult than taking an oil sample. Customers can take oil samples while the machine is still running. However, most of time, customers have to shut down the machine to take a grease sample or when machine is shut down so they can take grease sample.
Unlike oil, grease does not flow freely, making it harder to monitor and analyze consistently. There are many barriers to end-users adopting grease analysis. Many maintenance teams think that grease is a cheap consumable rather than a critical asset. On-site technicians often lack training to properly interpret complex grease lab reports. Older test methods require large sample volumes. High-quality specialized grease testing equipment requires a significant investment.
Proper sampling and the appropriate testing equipment at laboratories (I speak for South Africa).
Main barriers to adopting grease analysis may be technical sampling difficulties and that grease samples may not be representative.
Costs for expensive equipment and training of personnel/trained personnel.
Sampling is the main barrier. Many measurements require a larger sample size. This sample should consist of a relatively homogeneous mixture from the unit. Depending on the size of the unit, both of these requirements can be difficult to meet. In some cases, there is also a lack of sufficient accessibility.
Insufficient understanding of the complexities of grease.
The more difficult sample preparation (in comparison to oil analysis).
Lack of expertise and testing equipment.
Ability to collect a representative sample.
Less information.
Cost, the unknown, not understanding/being informed of the benefits.
Do you or your customers commonly use grease analysis?
Yes
37%
No
63%
Based on an informal poll sent to 15,000 TLT readers.
Q.2. What do you think are the most underrated condition monitoring technologies?
Vibration analysis.
Fourier transform infrared spectroscopy (FTIR).
Localized temperature monitoring with sensors.
Most companies don't fully understand the importance of regularly scheduled oil analysis. Random oil analysis tests don't deliver critical trending information.
Vibration.
Manual refractometer, with metal working emulsions.
Thermography.
Spectrometry—infrared (IR) and/or ultraviolet-visibility (UV-Vis).
The greases monitoring.
Oil temperature.
Ultrasonic sensing and
in situ optical grease sensors. Rather than relying on time-based greasing, these tools optimize lubricant change-out intervals and drastically reduce the risk of under or over-greasing.
Visual inspection of lubricants and lubricated parts by an experienced technician. Interpretation of laboratory results by experienced tribologist instead of chemists or artificial intelligence (AI). Temperature measurements showing heat created by friction on rotating parts.
Oil oxidation, particle counts.
FTIR analysis.
Ferrography.
Vibration analysis, ferrography techniques, laboratory evaluation of oils.
FTIR: quick, low maintenance, decent cost, rather versatile.
Consistent monitoring schedule.
Heat and sound technologies lead to grease analysis which tends to be ignored.
I don't know that most condition monitoring technologies are underrated, but I think many are misunderstood, in what they can and cannot do. The utility of the various inspection techniques available are not always clearly understood by both their advocates and their clients, leading to overblown expectations and inevitable disappointments.
Low implementation.
Online sensors.
Onsite capable systems.
Grease analysis definitely, and the most ultrasounds technologies.
Tribology properties in terms of oil wells drilling in high temperature and high pressure conditions.
Acoustic emission.
Ultrasound-assisted lubrication, wear debris analysis and machine learning-based fusion of vibration and lubricant data are still underutilized. These techniques can significantly improve early fault detection, especially for rolling element bearings operating under variable loads.
Monitoring at the equipment for noise, vibration, power draw, temperature and other operational variables that suggest a detriment of the lubricant.
Oil analysis.
Vibration analysis.
Online particle counting combined with improved contamination control.
Real-time analysis.
Heat condition monitoring on the sliding surface.
Various online analysis systems.
Visual inspection.
Technologies used in monitoring bearing condition are temperature monitoring and vibration monitoring. With AI technology in place, we can fully utilize AI to combine bearing temperature and vibration data to build models to stimulate the working condition and provide preventive maintenance recommendation.
The most underrated condition monitoring technology for grease is controlled oscillatory rheometry. Unlike traditional cone penetration tests, a rheometer requires less than 0.5 ml of grease, making it viable for small bearings.
No test or technology should be underrated or else people could miss important red flags.
Rheological properties.
Vibration training.
Oil analysis.
Nuclear magnetic resonance (NMR) spectroscopy.
Particle count and ferrography.
Training.
Acoustic emission analysis.
Do you or your customers use ultrasound greasing technologies?
Yes
23%
No
77%
Based on an informal poll sent to 15,000 TLT readers.
Q.3. Which area of oil analysis do you think needs more development?
Lost cost real time analysis, i.e., plug and play.
Real time oil sensors to gather data immediately.
Data analysis and utilization.
Measure of oxidation.
Sensors.
Microscopic analysis, or automation thereof.
Particulate analysis (ex. ISO 4406). In my experience, there are still issues with repeatability and reproducibility (R&R) related to this kind of analysis. Also, the ruggedness and accuracy of field/factory equipment is lacking.
Wear metal detection.
Greases analysis.
Temperature profile.
Ultrasonic test.
Taking good reference samples. Providing good information with lubricant samples like equipment and lubricant lifetime. Equipment and lubricant name, top-up. Analyze only at laboratories which know the equipment and not just the lubricant.
Oil oxidation and varnish determination.
Clear trending of analytical results.
Probably more AI integration to trigger re-sample, trend results, trigger actions and full equipment lifecycle alterations for preventative maintenance, mid-life re-builds and end-of-life reconciliation.
Ultrasound.
Oxidation stability, biodegradability tests, evaluation of plant-based vegetable oils as an industrial lubricant.
Tramp oil quantification.
End-user education as to the real value of a good condition monitoring program.
Connection to life span of bearings and other parts.
Automated particle identification combined with particle count and inductively coupled plasma (ICP) for wear evaluation.
Online sensors and automatic diagnosis.
Detecting compatibility issues.
Education of how to properly take a sample.
Additions for reducing of saturated vapor pressure.
Chemical analysis (online).
Easy to access technology and reliable and consistent results.
AI-assisted diagnostics, standardized interpretation for electric vehicle (EV) lubricants and e-fluids, real-time online oil monitoring and integrated multi-sensor condition assessment combining oil analysis with vibration, temperature and acoustic emission data require further development.
Support. Being here in Hawaii we are at the mercy of time differences, and sometimes getting someone who can relate to customers on a personal level without trying to sound like they are talking above the customer.
Driving the awareness of the potential benefits and rate of return.
Ferrography and FTIR.
Contamination detection.
Simple, visual test results to take the numbers off the report and provide a quick visual overview.
Useful life remaining of the lubricant. Not by hours or miles on the line but by the useful additives and analysis.
Molecular simulation.
Quick, easy to use on-site analysis kit to give a fast analysis of the oil/grease condition.
Online monitoring.
1.) EV and hybrid vehicle sales are growing very fast, and we need to develop more tests to monitor EV and hybrid vehicle driveline and engine condition which is new to the industry. 2.) Fully utilize AI to build large database of oil analysis for traditional ICE, EV, hybrid vehicle and other industrial equipment and build models to predict oil condition.
The area of oil analysis that needs the most development is real-time, in-line detection of complex chemical degradation, specifically additive depletion and varnish precursors.
More development is needed for e-fluids.
Rheology.
Onsite oil analysis in real-world applications. Many of the current analytical methods require laboratory conditions to yield reliable results.
Varnish (fluid damage/oxidation) or sludge (fine solid contamination/additive precipitation) determination to ensure correct fluid treatment solution used.
Vibration training.
End-user adoption.
Tribometrical methods.
Oil sampling techniques and online monitoring.
Turbines.
Improved tools to more easily determine contamination levels on site.
Editor's Note: Sounding Board is based on an informal poll sent to 15,000 TLT readers. Views expressed are those of the respondents and do not reflect the opinions of the Society of Tribologists and Lubrication Engineers. STLE does not vouch for the technical accuracy of opinions expressed in Sounding Board, nor does inclusion of a comment represent an endorsement of the technology by STLE.