The analysis of an oil sample from equipment in isolation only offers information regarding the status of the engine at the time of the sample taking, therefore, it is not a sufficient measurement for ensuring equipment availability and performance.
Carrying out oil analysis periodically in equipment is fundamental in order to find out its status, to lengthen its useful life and ensure that it runs at peak performance. For that purpose, the quality and representativeness of the oil samples are key concepts in the success of an oil analysis programme and, specifically, for ensuring optimal maintenance of the equipment.
A sample is representative when it is taken directly from the greasing system/circulation of the engine, at a working temperature and avoiding the influence of external contaminants as much as possible.
For this, an extractor pump known as a “Vampire” is used, which connects to the sample container. For sample taking in sumps or tanks, the extraction tube should be submerged up to halfway.
When samples are taken from grease lines or pipelines, the valves should be adequately cleaned allowing the oil to flow briefly before filling the sample container.
And if the sample is taken from a draining plug, a small quantity of oil should be allowed to flow before filling the sample container.
A sample is not representative when it is taken from a cold greasing system/circulation and/or with the motor stopped during a long period of time. For example, when the sample has been taken from a drain point such as the bottom of a tank, a draining plug (without purging beforehand), a tray or a recipient into which the oil has been emptied.
Neither is it representative when it is taken after being passed through filters, except when wanting to find out the level of efficiency of said filters.
It must also be taken into account that a sample must be analysed immediately after being extracted, if not it will not provide accurate information regarding the actual status of the lubricant and the engine.
Lubrication Management recommends analysing oil in equipment using its analysis to keep the engines in the best working conditions.