It's difficult to determine anything meaningful without a 'base-line'
record.. In otherwords spectrographic analaysis is done over an extended
period of time and the results of a current sample is compared to previous
readings. From all samples a trend can be determined and overhauls
scheduled.

Oil samples after a engine failure or from and engine that is about to fail
would however show high metal content, but then it is too late to take
corrective action.

Outfits with large investments in engines usually use some form of this
service as part of their preventive maintenance program..


--
My opinion and experience. FWIW

Steve
s/v Good Intentions