I've read from a couple of sources that the inexpensive type of oil analysis we do can read wear particles as large as 5 microns.(Terry claims 10 microns.) Molakule once said that when wear occurs, atomic-sized particles are released into the oil, and that these atomic-sized particles are the ones read by oil analysis. He went on to say that the amount of "wear atoms" released was proportional to wear. I've been thinking about this lately, and I wonder if the wear particles that FTIR-style analysis sees really are no bigger than atoms. When an alloy of two or more metals is made, they mix at the atomic level; that is, the different metals occupy interstitial positions of each other's atoms. So, if I file a bronze doorknob, for example, I don't get a small pile of copper and tin. I get bronze filings. If there is any copper or tin in the pile, then the particles are obviously atomic-sized. See what I'm getting at? Since most of the metals in an engine are alloys, and since FTIR-style analysis reads only elements, then the particles that are read must be no larger than atoms. Is that right? A .1 micron-sized wear particle of lead babbit bearing material, for example, would never be read by oil analysis because FTIR-style analysis can't read babbit--only lead and tin. Since steel is an alloy of iron and carbon, only atomic-sized particles of iron can be read? No? Please feel free to comment if you can shed any light on this subject.