Pore Blockage vs Optical Particle Counts

[Jim Allen]

2010FX4 and I had a chance to collaborate in an experiment that highlights the differences in two types of contamination analysis, namely an optical particle count and pore blockage, which is sometimes called a "particle count" but really isn't. Both methods are valid and have a place, so the idea here is not to diss one and praise the other but to show that they can't be easily or accurately compared. Perhaps this comparison will allow us to contrast them a little better, giving us some "offsets" to keep in mind when we look at these the results of two methods.

2010FX4 recently posted virgin “particle counts” of two oils he was analyzing for possible future use; Pennzoil Ultra 5W20 SM and Mobil 500 Super 5W20 SN. He had them tested at Blackstone, who use a Rockwell Automation Digital Contam-Alert tester, which is a pore blockage tester. Basically, the oil is filtered thru a screen and the restriction measured against a perfectly clean screen calibrated with a test fluid. The tester is attached to a computer and it interpolates the restriction and produces an ISO code and averaged particle count ranges. The pore blockage method is widely used and with very dark oil that makes optical counts impossible, it a very viable method. It’s useful for comparison purposes… before and after... or for maintenance. The pore screens used are often 10um in size so they are most accurate above 10 microns.

I convinced 2010FX4 to send me more samples of oil from the same bottles he had used for the pore blockage test samples. I sent them to a place that uses a SpectroLNS Q-200 Particle Counter, optical type. This tester counts the particles optically, even photographs them for a map of particle types, and delivers both an ISO code and a particle count. A computer then takes the results and presents them in ISO 4406, NAS 1630 and NAVAIR 01-1A-17 formats. We use the ISO 4406, which is commonly used in the automotive realms. I'll let you research ISO 4406 codes and how to interpret them There's plenty on the net.

As you will see below, the differences are stark. The optical numbers for the virgin oils are more in line with other virgin particle count tests I've found of new oil and when I saw 2010FX4's pore blockage tests, they really jumped out at me. Either I was using the world's dirtiest oil, the oils he tested were significantly cleaner than anything I had records on, or something was being lost in the translation between the two methods. Turns out to be the latter

As I said, I see value in the pore tests in that you can do before and after tests. It doesn't necessarily give you universally accurate numbers, but it will give you numbers you can work with and percentages with which to analyze what's going on. When you have really opaque oil, the optical testers are your only choice, really.


Below are the comparisons in counts per ml:



Code:
Mobil 5000 Super 5W20 SN (virgin)

Pore Blockage Optical



ISO 14/13/12 ISO 20/18/14



> 2um- 232 > 4um- 6076

> 5um- 86 > 6um- 1983

> 10um- 24 > 14um- 138

> 15um- 9

> 25um- 2

> 50um- 0

> 100um- 0





Pennzoil Ultra 5W20 SM (virgin)



Pore Blockage Optical



ISO 16/15/12 ISO 22/20/16



> 2um- 736 > 4um- 27,880

> 5um- 272 > 6um- 9270

>10um- 76 > 14um- 446

>15um- 29

> 25um- 6

> 50um- 0

> 100um- 0

 

[CarbonSteel]

Jim,

I appreciate the efforts placed into this so the knowledge base is expanded here on BITOG. Since additive packs components are sub-micronic (meaning those components do not show up in either test), what are your thoughts about the cleanliness of the two oils? For my part, even though there is such a wide disparity in the results between the pore blockage and optical tests, it would appear that MS5K is still "cleaner" than PU.

PS...I will be performing a blockage and an optical test on my next (last) OC of PU so that I can set a "standard" for the switch to conventional (either MS5K or PYB) in the FX4. Should be some interesting results.

 

[Garak]

Great stuff, guys. I wonder how much of a difference we'd see (in either methodology) from batch to batch of the same oil.

 

[Jim Allen]

Though I have a small verified sampling of oils at present, and more that I was given for which I do not have any context, the Mobil is within the range of of normal and at the cleaner end of it. I have another verified sample of the Mobil 5000 5W30 from last year and it's similar at 20/19/18.

I don't have permission, yet, from my source to post all the info, but I can say the cleanest bottled oil on the list is DELO 400 15W40 at 19/18/17 and the dirtiest is Mopar MaxPro 15W40 at 23/21/16. The list is heavy on HDEOs. I have some bulk oil tests that would make you hurl and vow never to buy bulk oil again. This appears to be a known problem in the lube industry but one that many in the retail side tend to ignore.

Garak: As to different batches, we see a little of that with 2010FX4's Mobil sample and earlier 5W30 sample (which was taken in Dec of 2011, so it's fairly current).

My evolving philosophy on this is that it's best to start out as clean as possible. Clean oil will stay clean longer at any filtration level.

 

[yucca]

I just looked at one of the last samples I had run of some bulk chevron delo 400 le was 18/13.

 

[Jim Allen]

Originally Posted By: yucca
I just looked at one of the last samples I had run of some bulk chevron delo 400 le was 18/13.


Run by what method, pore or optical? And did they give a three digit code as well?

I assume you do this to spot check cleanliness of a bulk system you use? If so, good on you! Evidently, too many people don't.

Some of the bulk samples I saw were 28/26/21. My poo comes out cleaner than that! ( : < )

 

[Garak]

Originally Posted By: Jim Allen
I have some bulk oil tests that would make you hurl and vow never to buy bulk oil again. This appears to be a known problem in the lube industry but one that many in the retail side tend to ignore.


I'm certainly not one to badmouth bulk oil; after all, if the only way a motorist is going to change his oil is by going to a shop and getting the cheapest oil change, which happens to be bulk, so be it. It's far better than no oil change, and the bulk stuff will/should meet the appropriate specifications.

That being said, I still prefer to do my own changes with my own bottled oil. That way, I'm relying on BP, XOM, SOPUS, etc. to ensure clean oil, rather than them plus the delivery system plus the shop's maintenance procedures.

 

[ltslimjim]

^I hear you guys loud and clear.

 

[Jim Allen]

RE Bulk vs Bottled: I didn't intend to come across as an alarmist, or as I like to say a "Chicken-Little" ("The sky is falling!"). I may have made it sound worse that it might be. I really don't know the extent of the problem. I have a few test results, did a little research and found some elements of "the industry" somewhat concerned. To the extent there is a problem, it comes from contamination of tanks not from the oil itself. Every time oil is transferred to another container, there is risk of contamination. From blending tanks to a storage tank; storage tank to transport tank; transport tank to the end users storage tank. It's logical to assume that blending tank direct to bottle and then sealed bottle is less risky in terms of contamination.

 

[yucca]

Originally Posted By: Jim Allen
Run by what method, pore or optical? And did they give a three digit code as well?
I assume you do this to spot check cleanliness of a bulk system you use? If so, good on you! Evidently, too many people don't.
Some of the bulk samples I saw were 28/26/21. My poo comes out cleaner than that! ( : < )


I'm just using the pore method that wear check offers. I check the the tanks at least once per annum. I also check my distributors tanks.

 

[ltslimjim]

Originally Posted By: Jim Allen
RE Bulk vs Bottled: I didn't intend to come across as an alarmist, or as I like to say a "Chicken-Little" ("The sky is falling!"). I may have made it sound worse that it might be. I really don't know the extent of the problem. I have a few test results, did a little research and found some elements of "the industry" somewhat concerned. To the extent there is a problem, it comes from contamination of tanks not from the oil itself. Every time oil is transferred to another container, there is risk of contamination. From blending tanks to a storage tank; storage tank to transport tank; transport tank to the end users storage tank. It's logical to assume that blending tank direct to bottle and then sealed bottle is less risky in terms of contamination.


You got it.

Besides, most posters here like buying/using their own oil. I will use a quick lube for a stop gap measure only.

 

[ltslimjim]

^Wanted to bump this, it is good information for those getting particle counts.

 

[GT350]

I have been in the business of using pore or mesh blockage in my business for about 25 years. I had the first unit built by Diagnetics that used a small Radio Shack computer and a dial indicator. Each time the indicator rotated past zero, you punched that into the computer until it stopped. Same as today, just manual input. Then progressed to their first dCA and now with the Rockwell, Entek, unit that uses Windows software and a much more powerful computer to do the cleanliness analysis.

After reading this thread, my question is why is anyone even looking at cleanliness analysis where engine oils are concerned? I have used my unit(s) on all types of hydraulic oils, turbine oils, water based fluids and other types of industrial oils, but never an engine oil. The filtration in an automotive engine could never clean an oil up to any level that this discussion talks about. Additionally, the viscosity of an engine oil would cause the instrument to run a very long time to get a result with a 10 micron screen and even the 15 micron screen would be a long time to a result.

I have compared the results from my instrument with optical instruments, and the results are never more than one level off on a NAS range or an ISO 4409 range and it will go back and forth as you run the samples. It seems that the lower the fluid viscosity, the better the correlation between the two methods.

Engine oil filtration is there for a reason, and getting to very clean levels cannot be achieved with that filtration, and I doubt that a super clean engine oil would mean anything to your engine anyway. I guess the question is, how many engines have ever failed because the new oil was not at some super clean level??? In fact, how many engines have failed because of dirty oil??

Mesh or pore blockage does not count particles as mentioned, but it gives you roll off cleanliness levels that tells you the general condition of the fluid with respect to particulate levels and whether or not you need to do some filtration work to achieve the spec cleanliness level.

 

[ltslimjim]

^This is more of a concern with establishing trending and engine 'health' relative to such trends instead of the time invested in pulling engines apart, such as a used vehicle or one you are trying to safely extend the intervals.

You could throw a bypass filtration system on an automotive application and suddenly oil cleanliness will improve, generally speaking as far as filtration. There is a dynamic involved that establishing trends relative to engine health with as much data sources possible helps one make a more definitive statement regarding said engine health/possible uses of oils relative to service conditions seen for one particular app.

Of course, folks do it for hobby as well. Others that are more concerned with good reasons; such as extreme interval extending, would have some use for testing such as outlined in the OP here, while using such in addition to regular UOA monitoring efforts.