Oil analysis
generic term for scientific examination of fluid properties, entrained wear and contamination for a variety of purposes. Selected goals and capabilities of oil analysis include:
| Assay | Tests are performed to examine and determine a sample’s characteristics, specifically related to the presence, absence or quantity of one or more substances. No conclusions are drawn past the quantitative results of the testing. |
| Specification | Selected performance-evaluating and assay tests are performed in order to compare a sample’s properties to known standards. Requires specification reference data (acceptable minimum / maximum values, and ‘typical’ values) for each parameter measured. Conclusions are drawn based on the comparisons / rankings of the unknown sample to predetermined target ranges in order to assess quality and performance in service. | Identification | A combination of assay and specification tests are performed in order to determine a sample’s manufacturing trade name and / or product designation, or to match an unknown sample to a known product. Requires advance knowledge of the specifications involved. Known references or chemical characteristics for each product may also be required if a complex mixture is to be separated by content, or if no specifications are available. Conclusions are drawn in terms of ‘match, no-match, sample appears to be…,’ with respect to the product in question. | Diagnosis | Assay, specification and identification tests are applied in conjunction with experience and statistics-based interpretation strategies, in order to assess the relationship between the result values and the fluid / mechanical condition of the system from which the sample was taken. Normally requires a time series of repeated measurements as well as individual requirements for the types of tests performed. Conclusions are drawn based on various maintenance and root cause analysis goals (see maintenance definition reference table). |
