Ferrography vs Oil analysis

Not open for further replies.
Nov 16, 2002
How does ferrography differ from what we see on here, which is spectrogphic? Is ferrography a more advanced method of determining wear?
Ferrography is an excellent method for determining the size distribution and type of wear particles. It is typically used if conventional oil analysis shows an abnormal wear pattern. Ferrography also captures particles > 5 microns that normally don't show up with an ICP "Inductively Coupled Plasma, or Rotating Electrode, "Rotode" type of test. The final thing that Ferrography does is to quantify the specific type of wear mechanism that generated the particles, ie rubbing wear, abrasive wear, corrosive wear, etc...

George Morrison from AVLube is the guy to talk to about Ferrography ....The test usually runs $90-$110 per sample.
TS- thanks.

Reason I bring this up is bc I really wonder if it's worth nit-picking all these UOA's like we do or even have a UOA done for that matter? As cary stated in another thread, I really think we over-analyze these things. How much difference can there really be with what we are seeing?

Most cars will last regardless of the oils used and that proves what we see in that most all oils will do the job. We don't see too much variation.
Aw c'mon buster, don't you believe in Santa Clause?


The physics department has come up with a new theory concerning the S. Claus phenomenon, namely, how it is accomplished. According to the physics people, who often commented upon the girth of S. Claus, suggests that the feat of global visitation coverage in one night can be explained by quantum gravity.

The girth suggests a gravity anomaly surrounds S. Claus causing chronological tidal effects, allowing enough time to accomplish global visitation coverage in what appears to be one night. Evidence for this is given by observation of the raindeer. Raindeer watchers know that the noses of flying raindeer rudolphus actually glow white. (This thermodynamics problem is being investigated).

The red colour reported by many, suggests that the white light is highly red shifted, indicating quantum gravity fluctuations at work. I, frankly, never understand what physicists are talking about. A much maligned group, and rightly so.

good one MK.
If you listen to what Terry has said, and look at the makeup of the oil, Redline clearly is the best built oil out there. However, it doesn't show the best wear numbers. I really wonder about spectrographic analysis. RL might look good under a Ferrographic analysis, who knows?
Thanks George. Sounds like it completes the picture of what is really going on.
As has been discussed elsewhere on this site, spectro is an excellent, relatively inexpensive method of oil analysis but does have inherent limitations. Those limitations being that the test is looking at particles generally smaller than 5 microns. Thus a failure or wear mode which generates large particles (camshaft failures generally occur in flaking, as example) may go completely undetected.
That is why a more complete analysis to include spectro and particle count is a minum when one is going to look at comparatives (oil/air filter testing, etc.) We will then have a complete spectrum of wear metals reported. The next step up is ferrography where the oil is examined under a slide which is exposed to a strong magnetic field, to align the wear metals. A trained technician then does a write up of the size, shape and possible source/causes of the metals showing on the slide. Ferrography combined with spectro/particle count is the closest thing to climbing inside a component one can have. However, as indicated, it is more costly as we now have a trained lab technician doing one oil sample at a time as opposed to spectro which is a batch, computer controlled process where a technican is processing 50 to 100 samples every 10 minutes.
But, yes, to have the complete oil analysis picture, a minimum of spectro + particle count should be used and the inclusion of ferrography to to get the total. Ferrography is used primarily as an analysis procedure for six figure engines, gearboxes, etc.. and can pay for itself with one catch of an impending failure.
George Morrison
Not open for further replies.