Info Centre >> Fuel and Lube Oil Technical Manual >> 6. Lube Oil - Sampling >> 6.3 Baseline Information for Oil Analysis
Baseline Information for Oil Analysis
In a busy operations and maintenance schedule, no one wants extra paperwork and record keeping. But, if an oil analysis programme is to furnish anything more than test data, the user must provide information on the equipment, components and lubricants in service.
Initial equipment registration can be easily accomplished by furnishing the laboratory with a consolidated equipment list, or by completing an individual registration form for each sampled component. Current operating data is then forwarded with each sample.
Oil Analysis: Sample Processing
An oil sample usually cannot be processed immediately if the customer name, unit and component identification, and sample date are not provided. If a particular machine has been previously sampled and the unit and component identifications do not match what was originally provided, testing may be delayed and the result not filed correctly with other oil samples for that machine. In addition to this ‘must provide’ data for each sample, also report any recent maintenance, change in performance or unusual operating conditions.
Specific individuals should be assigned long-term responsibility for this portion of the oil analysis programme. If this is not possible, then a particular department should be designated for involvement. Once this responsibility is established, a system of record keeping and correct sample identification should be initiated as soon as possible.
Oil Analysis Laboratory: Data Needed
One common false assumption is that an oil analysis laboratory can draw valid conclusions from the test results without any supporting data from the customer.
In completing oil analysis forms and sample container labels, the following brief definitions are helpful:
UNIT ID NUMBER - A unique reference number for an entire functional unit. Examples include an aircraft registration number, company asset or inventory identification or a vehicle serial number.
COMPONENT - The type of system, such as engine or gearbox, from which the sample is taken. Other designations such as ‘left’, ‘number 3’, ‘rear’ or an actual description of the component’s use, such as ‘fan-drive’, are also needed for clear identification. This data may be obtained directly from an equipment or component service meter, or from general operating records.
TIME SINCE NEW OR LAST OVERHAUL - The operating hours or miles since the sampled compartment was first put into service, or since the last overhaul was performed. Since normal wear rates change over the lifetime of a component and break-in may resemble abnormal wear, this information is needed for interpretation.
TIME SINCE OIL CHANGE - The number of hours or miles of component use between the time the oil was changed and the time the sample was taken.
OIL TYPE - The manufacturer, product name, and SAE or ISO viscosity grade for the oil that was sampled. Since there is often more than one blend of the same viscosity product, the complete name is very important in determining which testing reference oil should be used.
OIL CONSUMPTION or MAKEUP OIL - The amount of oil added to maintain correct oil fill level. Complete oil changes should not be reported as makeup oil or identified as ‘new oil’.