How To Read an Oil Analysis Report

The oil in a machine lubricates moving parts to reduce friction, regulates internal temperatures, and removes pollutants to ensure smooth operations. 

Sampling and analyzing the oil can help you evaluate several characteristics to inform future operating conditions, maintenance, repairs, and potential replacement. Interpreting an oil analysis report requires a short learning curve, but applying its insights is vital to optimal operational management protocols. 

The guide below explores an oil analysis report’s purpose and basic structure. Understanding how to read an oil analysis report is essential for implementing any suggested insights or recommendations. 

Partner with Cadence to maximize the benefits of oil analysis for industrial performance and longevity. 

What Is the Purpose of an Oil Analysis Report? 

After an oil sample is harvested from a heavy-duty machine or system and undergoes numerous tests, the results are compiled into an oil analysis report. 

Through strict harvesting protocols, various parameters of the sampled machine are also meticulously recorded — including operational conditions, the lubricant used, and any past maintenance or repairs. The oil analysis report factors all of this information into a comprehensive evaluation that companies can use to inform and refine future maintenance procedures. 

More specifically, an oil analysis report enables a business to monitor equipment health, adjust maintenance intervals, diagnose any existing issues, evaluate quality, and minimize downtime and repair costs. These capabilities contribute to successful ongoing operations as a type of proactive maintenance. 

After all, it’s a wiser financial move for many industrial companies to perform several oil analyses and evaluate the results than risk a potentially catastrophic failure and costly downtime. 

What Is the Basic Structure of an Oil Analysis Report?

The specific elements of an oil analysis report vary depending on the lab performing the analysis and any practices implemented in the process. 

Most have a section detailing customer contact information, the specific machine from which the oil sample was sourced, and the lubricant being tested. In addition to this administrative information, the oil analysis report typically includes data regarding fluid properties, contamination, and wear debris. 

Fluid Properties 

The oil within a machine typically consists of the lubricant itself, contaminants, and any wear debris that comes directly from the machine. In reviewing the fluid properties, the analyses determine the oil’s viscosity, acid number (AN), and base number (BN). 

The AN and BN indicate how the additives are performing, while the viscosity — which is vital to optimal performance for heavy-duty engine oils and motor oils — reveals the lubricant’s current state to determine if there’s been a shift. 

Contamination 

Elemental and moisture analysis provide actionable insights into contaminants within an oil. The study aims to identify contaminants and determine their origins. In addition to searching for pollutants, the analysis may also evaluate the potential for previously unnoted leaks from other fluids or lubricants. 

Wear Debris

Contaminants and wear debris are separate categories. Wear debris reveals what particles from the machine’s interior are entering the lubricant, not necessarily those from external sources. Wear debris can be common in the first few run cycles of a brand-new machine, flushing trace remnants of manufacturing or production processes. 

However, excessive wear debris typically indicates a significant operational issue that requires immediate attention. 

How To Read an Oil Analysis Report

Oil analysis reports evaluate oil samples based on their fluid properties, contamination, and wear debris. Further analysis includes elemental analysis, measures of viscosity, acid and base numbers, particle counting, moisture analysis, and ferrous density. 

Read on to learn more about how to read an oil analysis report based on common elements. 

Elemental Analysis

Elemental analysis — also called spectroscopy — evaluates oil samples using an inductively coupled plasma (ICP) spectrometer or rotating disc electrode (RDE). The results of elemental analysis are limited by particle size, but most report anywhere from 20-30 elements. 

Although it can be useful to look at individual elements, it’s far more valuable to consider trends in the elements that appear.

Labs often perform elemental analysis using Fourier Transform Infrared Analysis (FTIR). Lab technicians use infrared light to measure chemical compounds and detect contaminants like soot, antifreeze, water, and oxidation. Contaminants aren’t necessarily a red flag unless they exceed expected levels. 

The goal of elemental analysis is to discover what contaminants, wear metals, and additives are present in the oil sample. Ideal results should show low levels of contaminants and wear metals but higher levels of additives. Any results outside of those parameters should be carefully reviewed. 

Viscosity

Technicians report the viscosity of an oil measured at 140 degrees Fahrenheit for industrial oil and 212 degrees Fahrenheit for automotive oil. These temperatures indicate whether the oil has shifted viscosity or remained intact. Oil analysis reports typically cite viscosity in terms of kinetic or absolute values. 

Acid and Base Number

An oil’s acid and base number are closely related. The acid number indicates acid concentration, and the base number designates the oil’s alkalinity. Fluctuating acid and base numbers signal oxidation or that the incorrect lubricant was used. 

Particle Counting 

As the name suggests, particle counting involves measuring the size and quantity of the oil’s particles, including ferrous and nonferrous elements. Particle sizes range from greater than 4 microns to greater than 100 microns. Depending on the particle, a high concentration can indicate above-average wear. 

Moisture Analysis

The Karl Fischer test, also called hot plate or crack testing, measures the amount of moisture within the oil sample. Oil will naturally show some evidence of moisture, but too much can lead to corrosion and change the oil’s viscosity. Moisture often gets into a system through a bad seal or due to the condensation created during extreme temperature fluctuations. 

Ferrous Density 

Lab technicians can measure the ferrous density of an oil sample using electromagnetic fields. This test helps detect wear metals and ensures normal wear and tear. The amount of wear metal measured in ferrous density tests determines the severity of the machine’s wear and tear and where it is occurring. 

How Can Oil Analysis Reports Inform Future Maintenance? 

Any insights the oil analysis report offers should be evaluated in the context of the machine’s recent environmental operating conditions, runtimes, maintenance intervals, and any other relevant facets of machine management. 

In many cases, the best approach involves ranking each issue in severity and addressing the most severe concerns first. The main goal of each corresponding strategy is to remain proactive rather than reactive in ensuring optimal operating conditions. 

For example, if the oil analysis report returns findings that suggest above-average moisture content in the oil, the appropriate next steps would be to evaluate the machine to determine where the moisture is getting in. 

However, that may be less of a priority if the oil analysis report found that the incorrect oil was introduced into the system, and it may have prematurely shortened the machine’s lifespan. At that point, disassembly may solve both issues. 

Integrate Oil Analysis Into Your Maintenance Routine

An oil analysis report provides invaluable yet often cryptic information regarding the lubricants used in your company’s critical machinery. Cadence partners with top-tier oil analysis experts to help you identify essential equipment and test the corresponding lubricants to ensure smooth operations. 

Call us at 336-629-2061 today to discover how state-of-the-art equipment at our partner libraries can make a difference in your asset management and maintenance protocols. 

Sources: 

The Easy Guide to: Inductively Coupled Plasma- Mass Spectrometry (ICP-MS) | Duke University

Rotating Ring Disk Electrode Fundamentals | Pine Research Instrumentation Store

How an FTIR Spectrometer Operates | Chemistry LibreTexts

What is Karl Fischer Titration and How Does It Work? | News-Medical