Originally Posted By: Pablo
Originally Posted By: Jim Allen
Originally Posted By: benjamming
particle count from Blackstone is not real
What is that supposed to mean? Not real, as in "faked?" Not real as in the OP is listing false data? Not real as in Blackstone does it in some slipshod way? If you are making a serious charge against a well-known company, you should make yourself very clear and give a detailed account of what you believe to be true.
I can't pretend to be Ben, and I am not a particle count expert, but in a very short, simplistic nutshell - Blackstone does not do a standardized nor ASTM particle count. Some (including myself) have some serious doubts about the accuracy and precision of their machine method.
Originally Posted By: benjamming
Anyway, my point was summed up pretty well by Pablo. Ask them to provide you the standard # they follow.
Well, Ben, when I reread the above, it sure sounded like you were singling Blackstone out. Hence my comments. I think Blackstone provides a valuable service that we, the unwashed BITOGer can afford. I think they are worth a little verbal "standing up for" so I wanted to make clear what was really being said and take you to task if I thought you were being unfair.
And Pablo, I think you are incorrect also. Pore blockage IS a standard, accepted method. ASTM... I don't know for sure. In a limited search, I could only find an ASTM number for the manual particle count method, but not for the Automatic Optical Method. Both the Automatic Optical and the Pore Blockage have ISO, or [censored] certification, or its pending... per this:
Particle Counts
The pore blockage method is a common tool that even the "best" labs use. Even with clear oil, the automatic optical counter can be fooled by water and air bubbles, so they aren't 100 percent reliable either. When you have opaque oil, pore blockage may be the only available method, beyond a microscope and a human eye. Even the Mark 1 eyeball and Mark IV human brain can be fooled or make an error.
I may have an opportunity to have test samples of the same oil done via both methods and if I do, I will post it. I have some pore tests done by Blackstone and optical tests by another lab, but unfortunately, they are not of the same sample, so I cannot make a direct correlation. They are fairly close, however.