Which lab actually counts particles and sizes

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Nov 13, 2007
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I saw a post on here some time ago that some labs don't actually count particles and sizes but count some particles and then use some formula for extrapolation. So I am looking for a lab to tell me about the actual particle count and size in my used oil to test my filtration and how well my engine is doing. Links to websites or other contact information would be most appreciated. Thank you.
 
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If you really want a lab to count particles and sizes you will need to pay a lot extra (like $75) where they put the sample under an electro microscope and actually look at the sample. I was told that the places that have this done are places with huge gear assemblies used for manufacturing. OAI will do it.
 
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 Originally Posted By: DrRocket
I saw a post on here some time ago that some labs don't actually count particles and sizes but count some particles and then use some formula for extrapolation. So I am looking for a lab to tell me about the actual particle count and size in my used oil to test my filtration and how well my engine is doing. Links to websites or other contact information would be most appreciated. Thank you.
Wearcheck does it, however, considering how inexpensive they are, I don't know how reliable their data is, or even how they test it. I guess you could contact them and ask.
 
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They probably use the pore blockage method. It's detailed in the Bypass filter section. Basically, it's a metered amount of fluid passed through a membrane at a fixed rate. The upramp and rate of change in pressure indicates the "model" particle distribution. If the ramp is shallow and linear vs. steep and curved, for example .. The amount that this either resembles one or the other, and the pore size used in the membrane, gives them the "model" that conforms to that data. While not as accurate as the optical particle count, it has to have been validated by many optical count tests to make the technology viable. No one is going to spend that amount of money on a machine that can't do the job in some level of functionality. One would assume that one could just use dilution factors to make opaque fluids translucent enough for optical reading. I imagine that this requires certified particle free dilution fluids (oils) and adds error and drift as you add multipliers to your dilution factor. Polaris does PQ/optical/pore depending on what tests you order.
 

DrRocket

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Nov 13, 2007
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Thanks, I want to test the efficacy of the Micro Green filter that has a built in by-pass filter. The oil comes out next month.
 
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