Oil Analysis: A Complete Guide for Your Industry 

In industrial maintenance, tiny particles can hide big problems. Oil analysis is one of the most accurate tools for detecting internal wear, contamination, and lubricant degradation before they lead to mechanical failures. 

Over the past few years, the advancement of predictive strategies and the need to maximize asset availability have placed lubricants in a new light. Beyond fulfilling their functional role, they have become a critical source of information about component condition. 

That’s why, in this guide, you’ll understand the difference between lubrication and oil analysis, why simple scheduled oil changes are no longer sufficient, and what the most commonly used laboratory and in-field methods are. Additionally, we’ll show you how to interpret technical reports and present a step-by-step guide to implementing an effective oil monitoring program. 

What is the difference between oil analysis and lubrication? 

Although directly related, lubrication and lubricating oil analysis are distinct practices within industrial maintenance. Lubricating equipment means applying oil or grease to reduce friction between moving surfaces, control temperature, and minimize wear. Conversely, oil analysis investigates the condition of the lubricant and the signals it carries about the asset’s health.

Thus, while lubrication focuses on the immediate action of mechanical protection, analysis assesses the integrity of the lubricant over time—identifying contamination, oxidation, chemical degradation, and wear particles. In other words, the oil functions as a machine’s “blood test”: it carries clues about what’s happening internally, without the need for disassembly or invasive interventions. 

This distinction is crucial, as visually clean oil can be chemically compromised or contain metallic particles indicating developing failures. For this reason, maintenance strategies have been adopting the concept of a predictive lubrication program. This is a set of practices that combines technical inspection, laboratory analysis, and continuous monitoring technologies to ensure that lubrication and oil change actions occur at the right time, based on the fluid’s actual condition.

Why is oil analysis better than scheduled oil changes? 

The decision of when to replace lubricating oil in industrial assets directly impacts operational reliability and maintenance costs. Although the scheduled change model, based on usage time or operational cycles, is still widely adopted, it presents significant gaps. This is because it ignores the fluid’s actual behavior within the equipment and the factors that accelerate or slow down its degradation.

Oil analysis eliminates this uncertainty by providing objective data on the lubricant’s state, allowing replacement to occur at the technically appropriate time. Therefore, instead of changing the oil based on a generic estimate, the maintenance manager precisely assesses whether the fluid is still in usable condition or has lost critical properties, such as viscosity, additive content, or oxidation resistance.

This approach brings significant cost-benefit gains, as the oil is replaced according to actual performance changes, not before. This avoids both the premature disposal of lubricant in good condition and the risk of keeping a degraded fluid in operation, which compromises the lubricant film and accelerates internal component wear. 

Furthermore, analysis contributes to: 

• Increasing asset reliability, reducing the risk of failures due to inadequate lubrication. 
• Decreasing Mean Time To Repair (MTTR), as incipient failures are detected early. 
• Improving Mean Time Between Failures (MTBF), by preserving sensitive components through controlled lubrication. 

Which assets benefit from oil analysis? 

Oil analysis is especially recommended for equipment operating under continuous load, at high temperatures, or with severe work regimes. For example: 

• Medium and large industrial reducers 
• Rotary and reciprocating compressors 
• Gear or vane pumps 
• Closed-circuit hydraulic motors 
• Turbines and gearboxes 
• Transformers with insulating oil 
• Heavy mobile machinery (mining, agriculture, construction) 

In these assets, oil degradation directly affects performance, safety, and operational costs. Therefore, systematic lubricant analysis should be part of the maintenance strategy—integrated with other predictive tools, such as vibration and temperature monitoring. 

Oil analysis methods 

The choice of oil analysis methods must align with the industrial plant’s maintenance strategy and each asset’s operational profile. In companies with a large volume of critical assets, for example, it is advisable to integrate different approaches, combining in-field inspections and industrial oil testing in the laboratory, to obtain more complete and well-founded diagnoses.

Regardless of the technique adopted, one point is crucial for the reliability of the results: correct sample collection. However, a common mistake is underestimating this process. If the oil is collected with external contamination, in an inadequate volume, or without representing the actual operational conditions, the report may present distortions. 

Therefore, the collection procedure must follow strict protocols, with clean bottles, clear sample identification, and recording of data such as operating time and asset temperature. After collection, analyses are conducted according to the type of data sought. 

Below, see the main methods:  

Particle count: Direct evaluation of solid contamination 

Typically performed in the field or in industrial laboratories, oil particle counting identifies the presence of solid contaminants. These residues—such as dust, varnish flakes, metallic particles, and wear debris—indicate filtration failures, accelerated wear, or the ingress of external contaminants.

Results are expressed by ISO 4406 codes, which indicate the concentration of particles in three size ranges (≥4μm, ≥6μm, and ≥14μm). A sudden increase in these values signals progressive component wear or the need for a review of the filtration and sealing system. 

FTIR: Spectroscopy to assess chemical degradation

The FTIR (Fourier Transform Infrared Spectroscopy) test is a laboratory technique that uses infrared spectroscopy to identify chemical compounds present in the oil. With this method, it’s possible to detect, for example: 

• Oxidation and nitration 
• Presence of water or fuel 
• Additive degradation 
• Acid formation 

FTIR spectroscopy in oil is a precise and sensitive analysis that allows for monitoring the useful life and behavior of additives over time. Therefore, this information is fundamental to avoid premature oil changes or operating with degraded fluid.  

Ferrography: Qualitative and quantitative wear analysis 

Ferrography is an advanced examination aimed at studying the metallic particles present in the oil. The objective is to understand not only the quantity but also the type of wear occurring within the equipment.

There are two main types:

• Direct ferrography, which quantifies the concentration of particles. 
• Analytical ferrography, which uses microscopy to identify the morphology of the particles (adhesive wear, abrasive wear, fatigue wear, corrosive wear, etc.). 

By recognizing wear patterns with predictive diagnostics, it’s possible to anticipate mechanical failures and define corrective actions before they become critical. 

How to interpret an oil analysis report

The correct interpretation of an oil analysis report is what transforms laboratory data into technical decisions. The document typically compiles physical, chemical, and contamination parameters, compared to predefined limits to indicate the condition of the lubricant and the monitored asset.

Main report columns 

Reports may vary by laboratory but generally contain the following sections: 

• Sample identification: Includes asset number, collection point, date, and time. 
• Physical and chemical parameters: viscosity, Total Acid Number (TAN), additive presence, oxidation, and nitration. 
• Contamination: Presence of water, glycol, soot, silica, or other contaminants. 
• Metallic wear: Levels of iron, copper, aluminum, chromium, tin, among others. 
• Alert limits: Each parameter has normal, cautionary, and critical ranges, according to international standards or manufacturer references. 

These data are analyzed in an integrated manner. For example, an elevation in iron combined with low viscosity may indicate accelerated wear caused by deficient lubrication. 

Below, we provide a real example adapted from an in-field technical report analyzed by the Dynamox team, on a critical asset in the mining industry. The data was extracted from an implemented oil analysis program: 

The integrated analysis of these parameters allows not only for detecting specific anomalies but also for understanding the asset’s behavior over time. In the example presented, the low viscosity coupled with the critical presence of particles demands immediate intervention and a review of the lubrication plan. 

Therefore, by correlating physicochemical and spectrometric data, the technical team can act with precision, prioritizing critical assets, adjusting collection intervals, and reducing unforeseen downtime, always based on evidence. 

Step-by-step guide to implementing oil analysis in your plant 

Effectively implementing an oil analysis program starts with a technical diagnosis of the plant and a detailed mapping of assets. Below, we present a practical roadmap to guide this implementation, focusing on reliability and data-driven decision-making. 

1. Defining critical points and sampling frequency 

The first step is to identify which equipment is critical to operations and which of those use oil lubrication. Criticality should consider variables such as production impact, downtime, maintenance cost, and failure history. 

Once assets are defined, you need to establish the ideal collection frequency. This frequency can vary from weekly to semi-annually, depending on the operational regime, the severity of working conditions, and the equipment’s history. Furthermore, assets exposed to high loads, contaminants, or elevated temperatures generally require more frequent monitoring. 

2. Choosing the method: Laboratory vs. Sensors

Manual collection with laboratory submission is the traditional method and allows for in-depth analyses like FTIR and ferrography, which are fundamental for identifying the origin of wear and chemical degradation.

However, sensors offer additional advantages in data collection and analysis. Dynamox solutions capture information about asset health that can be correlated with oil and lubrication issues, integrating them into the plant’s monitoring system. This allows for rapid detection of condition deviations, triggering smart alarms, and preventing incipient failures.

Combining in-field sensors with laboratory analyses is a recommended practice for companies seeking excellence in reliability, as it combines diagnostic depth with response speed. 

3. Integrating results into the maintenance strategy 

All data obtained—whether from sensors or laboratory reports—should be centralized on an analysis platform. This facilitates trend monitoring, correlation with other data (vibration, temperature, current, and voltage), and technical decision-making based on asset history and behavior.

The Dynamox Platform, for example, allows for seamless centralization, organizing information by asset, generating reports, comparative dashboards, and the ability to calculate indicators like MTBF and MTTR, as well as alarms based on custom limits.

Tangible benefits and success indicators 

Oil analysis, when structured as part of a predictive maintenance strategy, delivers practical benefits that go beyond lubricant protection. Its impact is directly reflected in asset reliability, reduced operational costs, and continuous improvement in performance indicators.

Here are the main benefits of oil analysis: 

Reduction in oil consumption and unplanned downtime 

By monitoring oil condition, fixed-interval changes are avoided, which often results in the premature disposal of still-functional fluid. This makes it possible to reduce lubricating oil consumption without compromising component protection, leading to direct cost savings on consumables.

Additionally, by identifying contaminants, thermal degradation, or metallic particles in early stages, analysis allows for corrective actions before they escalate into severe failures. This reduces the number of emergency interventions and unplanned downtime for your company, especially in highly critical assets.

Improvement in key maintenance KPIs 

Integrating oil analysis into a structured reliability program positively impacts key industrial performance indicators: 

• MTBF (Mean Time Between Failures): Increases as failures caused by internal wear and deficient lubrication are prevented through early diagnostics.
• MTTR (Mean Time to Repair): Tends to decrease, as planning interventions based on data allows for preparing teams, parts, and maintenance windows in advance.
• Operational Availability: Rises due to the reduction of unexpected failures, improving production rhythm and the utilization of asset lifecycles.
• Reliability: Recurrent lubricant analysis serves as an indirect indicator of equipment health, strengthening predictability and operational safety. 

These benefits make oil analysis an important pillar within Reliability-Centered Maintenance (RCM) strategies, especially when combined with continuous monitoring technologies like Dynamox sensors. 

Frequently Asked Questions about Oil Analysis (FAQ) 

1. What is the ideal sample frequency? 

The ideal frequency depends on the asset’s criticality, operational environment, and load regime. Critical equipment or that exposed to high temperatures and external contamination generally requires monthly collections. Assets with more stable operations can be monitored quarterly. Most importantly, the periodicity should be defined according to a technical risk analysis, also considering failure history and the maintenance strategy adopted by the plant.  

2. Do I need to use all methods?

Not necessarily. Each analysis method serves a specific objective:

• Particle count: Indicated for evaluating solid contamination and abrasive wear;
• FTIR (Fourier Transform Infrared Spectroscopy): Useful for identifying chemical degradation, oxidation, and the presence of organic contaminants;
• Ferrography: Recommended when you want to investigate the origin of metallic wear. 

The combined use of these methods is ideal in advanced predictive maintenance programs, but the choice should be guided by the type of asset, most probable failures, and available resources. In many cases, a staged approach is sufficient—starting with basic methods and expanding as the plan matures. 

3. How do I create an oil analysis checklist? 

Developing an efficient checklist for oil inspection should start from a structured maintenance plan. From there, the checklist functions as a tool for standardization and operational traceability, guiding the field technician to perform a representative and safe collection. 

Below, we highlight the main items to check: 

This type of technical checklist facilitates quick screening for non-conformities, ensuring that sample collection occurs under ideal conditions and that the subsequent diagnosis is reliable. 

Evolving in monitoring is a strategic decision 

Oil analysis is an essential tool for ensuring the reliability and longevity of industrial assets. More than a complementary practice to lubrication, it offers a deep insight into the internal behavior of equipment, allowing for the detection of incipient failures, reduction of unnecessary oil change costs, and optimization of maintenance resources.

By integrating laboratory methods and sensors, it’s possible to reach a new level of control and predictability in operations, aligning safety, productivity, and economy. This predictive approach transforms oil into a true strategic ally in asset management. 

Dynamox offers complete solutions for this journey. Wireless sensors, a digital platform with dashboards, and smart alerts allow for continuous monitoring of asset health. 

Want to take your maintenance strategy to the next level? Talk to a Dynamox specialist and discover how our technology can support your plant in data-driven decision-making.