Particle Count Reproducibility

[Ericm]

I'm planning to compare several oil filters using VOA as a baseline. Besides the many variables that can skew any meaningful results, I'm concerned about:
1. Accuracy of particle counts that accompany oil analysis.
2. Variability of particle content of virgin oil.
Does anyone know how reliable particle counting is?
Any ideas about how much difference there is in particle content of an oil brand within an identical lot number and time code which is printed on the bottle?
From what I've read in the Virgin Oil Analysis Library
http://www.bobistheoilguy.com/voalibrary.html
VOA particle counts can vary widely from lot to lot of an identical oil brand and weight.
For example Delo 15w-40 http://63.240.161.99:8080/bitog/voalibrary/delo-15w40.jpg
I'm planning to use identical lot number / time code for all filters I plan to test. I hope the particle content from bottle to bottle is close to identical.
Any ideas or experience welcome.

 

[bruce381]

contact Bobby at Analysts Inc. Oakland Calif he can tell you.
bruce

 

[SWHeat]

Here is a link for you to check out. Oil Analysis Margins of Error

It specifically talks about particle counts in the eighth paragraph.

 

[Gary Allan]

I don't think you have to go to all this trouble. The proof in the filtration typically means a lower cutoff of larger particles. If you look at most PC, there's a progression as you go smaller. It's not a directly proportional escalation of particles ..but does gravitate toward a 3:1 advancement as you go smaller. You may get one or two larger particles ..but once they're in the double digit numbers ..it works out from there.

For example, Msparks used an Amsoil bypass filter for extended drain. It had tons of >2um and >5um particles ..but virtually nothing above that. Great filtration.

If you want to check the lab for reliability and repeatability ..just use two labs and send them two sample each from the same sump

 

[XS650]

Quote:

---

Here is a link for you to check out. Oil Analysis Margins of Error

It specifically talks about particle counts in the eighth paragraph.

---

I believe you are confusing particle count with ppm because of an unfortunate choice of words on the Spacebears site.

 

[427Z06]

Quote:

---

If you want to check the lab for reliability and repeatability ..just use two labs and send them two sample each from the same sump

---

This might be the best idea since a lab's accuracy and precision will be dependent on not only their equipment, but their calibration procedures and their repeatability on how often they need to calibrate versus how often they actually do it.

 

[SWHeat]

Quote:

---

Quote:

---

Here is a link for you to check out. Oil Analysis Margins of Error

It specifically talks about particle counts in the eighth paragraph.

---

I believe you are confusing particle count with ppm because of an unfortunate choice of words on the Spacebears site.

---

Did you read the article? Did you read paragraph eight?

 

[XS650]

Quote:

---

Quote:

---

Quote:

---

Here is a link for you to check out. Oil Analysis Margins of Error

It specifically talks about particle counts in the eighth paragraph.

---

I believe you are confusing particle count with ppm because of an unfortunate choice of words on the Spacebears site.

---

Did you read the article? Did you read paragraph eight?

---

Yes,

Quote:

---

Particle counts are determined through spectrometric analysis. In this process, a spectrometer examines the wavelength of particles in the oil and determines their concentration in milligrams per kilogram (mg/Kg, or parts per million). The repeatability of this test is amazing, down to one or two mg/Kg for many elements, but the reproducibility is two to four times less precise. This is one area, in particular, where advancing technology could well improve the test's precision to levels greater than the industry standard.

---

He talks about particle count, then switches to mg/kg in the same paragraph. The only data he showed was was ppm, or mg/kg data. Where do you get an understanding that he is truely talking particle count instead of ppm?

 

[SWHeat]

Yes, I understood it. Yes he uses the wrong nomenclature. Did you understand the difference between repeatability and reproducability? The point of the article?

Blackstone Particle Count article This should make you happy, but says nothing of reproducibility or repeatability of the test.

I'm awake now...have a good day.

 

[XS650]

Quote:

---

Yes, I understood it. Yes he uses the wrong nomenclature. Did you understand the difference between repeatability and reproducability? The point of the article?

Blackstone Particle Count article This should make you happy, but says nothing of reproducibility or repeatability of the test.

I'm awake now...have a good day.

---

Yes I understand it, but that wasn't what I was commenting on. I was commenting on you referring people to a paragraph on particle count that didn't say anything about particle count, except that it misused the term "particle count" when it should have said ppm.

It didn't talk about particle count any more than a cake recipe that mistakenly calls flour astrophysics is a discussion of astrophysics.

 

[SWHeat]

XS650, my bad. You are correct. I should have been more cautious. It is possible that repeatability and reproducability are not the same for the particle count test and the ppm testing for UOA. The idea of repeatability and reproducability, you would think, would be the same for both.

Bad assumption.

Why do you have to keep editing your posts? There is a preview before posting. More importantly, HOW do you edit your posts?

 

[XS650]

I'm egotistical enough to assume that my post is correct the first time I post it, but realistic enough to see that it wasn't when I read it

Hit reply, then go to the address bar and change "newreply.php" to read "editpost.php", then hit enter and you will be in the edit screen. Intuitively obvious

 

[Gary Allan]

Hit reply, then go to the address bar and change "newreply.php" to read "editpost.php", then hit enter and you will be in the edit screen. Intuitively obvious

(visions of McCoy's response as Spock ponders aloud variables that he cannot compensate for)
Naturally

Quote:

---

This might be the best idea since a lab's accuracy and precision will be dependent on not only their equipment, but their calibration procedures and their repeatability on how often they need to calibrate versus how often they actually do it.

---

I'd even go further and send the samples in two different batches (one to each lab = one batch) with a time span between them of a few days. What would be disappointing is if you got 4 results that were all over the board. Hopefully you would get all 4 within a decent margin of error. If they're calibrating incorrectly ..but doing it in a consistantly incorrect manner ..then you should get two pairs of like data. Where you go from there is probably to a third lab

 

[Ericm]

427Z06 and Gary Allan, I agree with both of you. Maybe I'll call some labs and ask how often they calibrate. I'm also curious if operator technique can alter results. I'm trying to decide how much money I want to budget for this experiment. These tests can add up to more than the cost of all the most expensive oil filters I will ever buy for the rest of my life. But, I'm thinking maybe $200 max...

 

[Gary Allan]

Quote:

---

These tests can add up to more than the cost of all the most expensive oil filters I will ever buy for the rest of my life.

---

..but think of the pride of boldly going where few (or no) BITOG member has gone before. You can also imagine many members genuflections as you pass by with a monarch-like wave.

These sort of things you can't give a $$$ value to. They're priceless.

 

[Ericm]

Careful Gary Allan, my head just might over inflate larger than the extra-oversize filters I plan to use.