These include original equipment manufacturers (OEMs), lubricant manufactures, industry accepted maintenance standards, and internal ALS data used to compile statistical analysis of test results on equipment.
- Wear metals flagging limits are generally reliant on OEM specifications and technology using ALS Tribology statistical analysis of data.
- Lubricant properties are dependent upon lubricant manufactures property limits for fluid life and performance integrity.
- Contaminant limits are compiled based on lubricant tolerances, equipment design performance and health requirements, and work environment.
As test results evaluation criteria are established for in-service lubricants, diagnosticians follow guidelines to assess equipment health and product integrity. In addition, equipment that is under warranty should always comply with OEM guidelines for testing of in-service lubricants and warranty criteria that have been established for wear metals, lubricant properties, and contaminants. In some situations compliance regulations related to environmental requirements or safety standards will also affect flagging limits for test results evaluation for certain applications.
During the diagnostic or evaluation process, a warning or condemning notification on a test report generally requires assessment of multiple factors associated with the sample that was tested. Diagnosticians will look at a matrix of test result parameters related to both the oil and equipment information. Different makes and models for similar types of equipment can have unique wear metal flagging limits, but this is also affected by work environment and the age of the equipment and age of the lubricant in service.
There are times when a diagnostician will not wait for a single test parameter to reach a condemning limit before indicating a problem on a test report. An accelerated increase or rate of change from the previous sample for the time on the oil can raise a warning flag.
There are also situations where a test report is flagged when a combination of test results are heading in a detrimental direction, yet no single test results has reached a condemning limit on its own. When reviewing the subtleties of the data on an in-service lubricant test report, having complete information provided when the sample is submitted allows for a more complete analysis of the equipment.
Overall, test reports and specific test results are categorized by ALS diagnosticians into four categories. Normal, Caution, Abnormal and Severe. When a condition level above Normal is noted on a test report it is indicative of the need for awareness or action.
- Caution condition is meant to note a situation that the client should be aware of. No action is required but the situation should be monitored.
- Abnormal indicates a condition where a decision needs to be made whether the person(s) responsible for the equipment can live with the situation or not. If corrective action appears to be required then the scope of the problem should allow maintenance or changes to occur in a timely fashion that is least disruptive to schedules and workflow.
- Severe condition indicates that immediate corrective action is required in order to prevent further damage or impending equipment failure and work interruption.
There are times when it is advantageous for a customer to consult with an ALS Tribology laboratory or diagnostician regarding information provided on a test report, which in many instance will increase the value of the data reported and improve any corrective action decisions that may be necessary.
David Doyle, CLS, OMA I, OMA II
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