dnewton3
Staff member
Yeah, here's where a UOA is a bit ambiguous ...
High PPM of Fe or Pb can be concerning in short OCIs, but long ones can simply show the gradual accumulation of those items.
And since UOAs only measure content by percentage and not particle size, you really have no idea if the 40 ppm of Pb would be 40 units at 1um in size, 20 units 2um in size, 80 units .5um in size, etc. Get it? As long as the particle sizes are small (less then 5um) and they stay that small, there is little (if any) real damage being done, and they are most likely shed from oxidation rather than wear.
At this point, I'd say this load of oil is still OK to use. But everyone has a different comfort level.
High PPM of Fe or Pb can be concerning in short OCIs, but long ones can simply show the gradual accumulation of those items.
And since UOAs only measure content by percentage and not particle size, you really have no idea if the 40 ppm of Pb would be 40 units at 1um in size, 20 units 2um in size, 80 units .5um in size, etc. Get it? As long as the particle sizes are small (less then 5um) and they stay that small, there is little (if any) real damage being done, and they are most likely shed from oxidation rather than wear.
At this point, I'd say this load of oil is still OK to use. But everyone has a different comfort level.