Understanding the Importance of Evaluations in Oil Sample Reports

It’s often easy to decide what to do when an oil analysis lab report returns a ‘normal’ or ‘critical’ evaluation.  But what about the other evaluations that aren’t so definitive?

Most labs will have an equivalent evaluation to ‘caution’.  It could be described as a ‘monitor’ or ‘B – corrective action may be required’.  This can be interpreted in many ways and generally they are telling you that something is not ‘normal’, but the severity or origin of the issue is unknown.  This presents a decision for the Condition Monitoring Technician whether to investigate further or leave until the next sample to monitor the trend.  The problem with either of these approaches is that they can potentially increase workload unnecessarily or worse still, allow a problem to advance to a more troublesome failure mode between samples.  These sample evaluations are essentially a caution to a potential issue but how much work should be put into investigating the potential issue further? 

Bear in mind, the evaluation is subjective and applied by the Lab Technician based on the oil analysis result. 

It’s the Lab Technician's interpretation of the data which may vary depending on who is doing the analysis.  In the case of a Diesel Engine compartment, they may suggest that an Elevated infrared results may be caused by increased blowby, incorrect operating temperatures and/or extended oil change intervals.” and to “Check for possible blowby or overheating then resample at half the recommended interval.”  This presents quite a broad range of actions that would be time consuming to complete for all similar evaluations.  Especially when the increased results may be due to a faulty ROS (reserve oil system) and reduced sump capacity, which can have the same effect on the oil condition as blow-by, increased operating temps, or extended oil drain intervalA balanced approach needs to be taken when reviewing the ‘caution’ evaluated samples in the report.  Understanding the data and trends will be the best approach to further delve into the sample results. An experienced Condition Monitoring professional will be able to interpret the sample data and have a reasonable idea of what needs to be done (investigate, ignore or act).  Ignoring them should not be an option. 

Spending time investigating problems that don't exist is costly and takes the focus away from work that needs to be completed.

Oil analysis is one of the best ways to understand what is happening in your components and the most subtle changes in analytes can be the catalyst to take action to prevent wear and potential failures.

Acting on oil sample report data is essential to get the greatest value from your sampling program.  A ‘caution’ sample shouldn’t be ignored, but it also needs to be considered thoroughly to ensure that any action taken is adding value and not wasting technicians time or resources.   

The Relialytics Equipment Condition Supervisor (ECS) doesn’t have an evaluation criterion like a lab.  It evaluates the data and there is either a specific action to be taken, or there isn’t.  There’s isn’t any subjectivity or ambiguity on what to do, it’s all based on the data.  One of the benefits of this is the reduction of what we call “noise”. It’s the samples that the lab raises as a flag but without any specific action to be taken apart from a component check or a shortened sample interval.  The ECS will create a recommended course of action based on samples that need attention no matter the severity.  This reduces speculative investigations and time spent chasing a problem that may not exist.  

When you look at your oil sample reports in future, consider the ‘caution’ samples more carefully and make sure that you give them the attention they deserve.

Do you have any thoughts on this blog?  We'd love to hear from you.