factors distorting particle count readings

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A recent hydraulic oil analysis report showed a 20/15/11 cleanliness code but was rated "normal" by the lab/vendor. Oxidation, nitration and Ultracentrifuge reading where minimal. The only contamination element showing anthing was Boron.

When questioned about the desparity between the report and the recommmended targets from several outside resources, the response was there were many other factors that influence cleanliness readings.

Noria training refers to 10 factors (e.g. additive floc, sludge, air bubbles, fibers) that have impact on light blocking or scattering values.

Should we not expect the lab to compensate for those factors? (like the procedure listed in the Noria training for water.) And thus produce a report that means something?

Should we use a different particle counter technology? (e.g. Pore blocking)

Are there levels or degrees that the factors above can be measured to decide if/when to ignore the cleanliness readings at all?

9/21/0510:39 AM

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mrhughesMember

I belive it is diffircult for the lab to compensate for counts that in fact are not particles, unless they either use a more advanced type of particle counter (Like LaserNet Fines) or good old optical microscope.

9/22/0510:57 AM

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johnmMember

I think you are concerned about secondary things. Your primary focus should be to find a way to clean up your dirty oil, by either through an aggressive filtration process or by attaching an off-line filtration unit (dedicated or portable). Once you get oil cleaned, you can send filter element to a lab to find out what was in the oil.
As for analyzing the cleanliness and having confidence in such reports, I suggest you send samples to two different labs requesting ISO 4406/99 method (results reported in >4, >6, >14 µ). These analyses are dirt cheap and anyone can afford to do it.
For best results of monitoring and controlling cleanliness of your oil could be achieved by portable particle counter (if you can afford one).

9/23/059:46 AM

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lubemateMember

Trending your results using regular oil analysis would assist in overcoming the short comings but not completely eliminate them. Their is just to many variables that could affect a particle count result, bottle cleanliness, sampling method, sampling equipment, person taking the sample, etc. All this before it even gets to the lab.

Trending is a powerful tool.

I disagree with John's comment on obtaining best results using a portable particle counter, a laboratory standard particle counter degasses the sample before analysis and in my opinion, should give more repeatable and accurate trendable data. In a lab there would be procedures to follow with each sample and it is done in a controlled environment further enhancing repeatable results.

9/28/054:40 AM

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