eSource: Equipment condition monitoring through fluids analysis


ALS has maintained its lead position in asset integrity and reliability by continuously seeking the most effective oil condition monitoring techniques, enabling clients to maximize asset life and return on investment.

If not actively using a structured in-service lubricant and coolant analysis process what are you missing? Testing assets is not expected to be a one-off maintenance activity to be used only when problems are obvious or suspected.

Testing of in-service fluids in operating equipment is optimally geared for predictive maintenance and proactive maintenance. When performed properly testing will optimize planned maintenance and scheduled downtime. The activity is meant to compliment other predictive maintenance tools such as vibration analysis, thermography, and ultrasound.


Testing of in-service lubricants and coolants looks at both asset performance reliability and fluid performance and service life, including:

  • Trending wear and predict failure modes
  • Monitoring and control contaminant levels
  • Evaluating lubricant and coolant properties and degradation
  • Monitoring environmental and operating conditions

In selecting equipment assets for condition monitoring using fluids analysis some criteria may be considered:

  • How critical is the equipment to the operation and what is the penalty of failure if the equipment goes down expectantly?

    • What are the downtime and repair costs with and without using oil analysis?

    • What is the general cost to business interruption when equipment breaks?

  • How is my warranty protected on new equipment?

  • How is the resale value of old equipment increased?


In establishing test scope for asset reliability answers to some questions should be reviewed:

  • Have goals for applying the test data been established?

  • Does the scope of testing provide KPIs towards these goal?

  • Does the testing provide return on investment and root cause monitoring

  • Who has ownership for review and follow up of the data?


Maximum returns are realized when maintenance practices are aggressively correlated with the information provided by a structured fluids analysis process. Many of the cost benefits of incorporating lubricant and coolant analysis into a company’s maintenance practices will depend upon how it is used and managed.

Most maintenance practices using fluids analysis fall into three categories:

  • Preventative, Scheduled Maintenance

    • This can lead to too much or too little maintenance and is often not relevant to the actual condition of equipment.

  • Predictive, Condition Based Maintenance

    • Maintenance decisions based on current health condition of equipment and how critical the equipment is to the operation and cost of downtime. Data is used for scheduling corrective maintenance that is least disruptive to operations.

  • Proactive (Root Cause Analysis), Condition Based Maintenance

    • Control or eliminate the source of root causes that lead to equipment or lubricant failure. This practice provides the most benefit for asset reliability and involves managing contamination thresholds, triggers for accelerated wear, and optimizing drain intervals.

Small sump size does not necessarily mean testing is redundant. It may be inexpensive and easy to just change oil when product issues are suspected, but the other half of the equation is the health of the equipment itself, which is relevant regardless of sump size.

Consistency in the testing process is key. Equipment service duty, environment, and general operating conditions provide characteristic wear patterns that trending analysis uses as a baseline. Consistent sampling practices for taking a representative sample are key to good data. Installation of sampling ports for consistent and convenient sampling of equipment is recommended. 

A good testing program goes beyond just sending in a sample and receiving a report on a single piece of equipment. One-off testing is not the best application of in-service fluids analysis. Trending is the best application. Take advantage of all reporting tools and management reports provided by the laboratory. Look at the data from the perspective of plant-wide or fleet-wide overall health, not just from the viewpoint of testing based on individual reports for individual assets.

For further information on implementing a fluid analysis program, contact the equipment reliability team.