[ April 10, 2005, 03:35 PM: Message edited by: 59 Vetteman ]
That is a good point, but apparently not. I have oil samples with and without bypass and the additive package did not decline with the bypass.quote:
Originally posted by MDD30240:
At those particle counts it looks like a bypass filter would be removing part of the additives. Is it enough to matter?
The particle count will tell you particles >5 microns and >15 microns. There are 2 numbers, such as 21/17. These numbers correspond to a particle count range. The numbers are meaningless without a baseline, such as a particle count for new oil, a typical particle count for a used oil, or a typical particle count for used oil with a bypass. Then you can compare. The cleanest particle counts are required for hydraulics since the pressures are so high. Can be useful info occasionally. I am doing it because of extended oil drain intervals and use of a bypass. Just want to see how the bypass is working. SPICERquote:
Originally posted by T-Keith:
Good info. Are particle counts useful at all with a VOA? What size range of particles are measured in a oil analysis?
I am beginning to question the wisdom of trying to filter the oil to 16/13 before use. We are seeing (and learning) that many of these particles are indeed additives and they most certainly are filterable. The reason the additive levels do not appear to be affected by filtering is the ICP instrument does not see these "big" particles so when they are removed there is no change. I don't know to what extent this affects the oil's performance but I can't help but wonder. I have recommended to our parts and service people that we do a microscope analysis on new bulk oil before we try to "clean" them up.quote:
Originally posted by SPICER:
That is a good point, but apparently not. I have oil samples with and without bypass and the additive package did not decline with the bypass.quote:
Originally posted by MDD30240:
At those particle counts it looks like a bypass filter would be removing part of the additives. Is it enough to matter?
A "ferrographic" oil analysis will tell you particle count and it will also tell you "what" those particles are. But at $100 it is pricey. SPICER
You really need a microscope analysis to see what type of particles are present. We see lots of samples that are severely contaminated with metal and dirt and we see some that appear to be additives. The particle count serves as a screening tool to help identify potential problems.quote:
Originally posted by T-Keith:
Good info. Are particle counts useful at all with a VOA? What size range of particles are measured in a oil analysis?