Indeed, but how can you get significant harmful particulates when the horizontal vis is tens of nm?
oil samples are taken from engines and checked on a regular basis to predict wear and/or imminent component failure. I used it in the FAA on Lynx engines.
Oil analysis is done by most higher-end GA owners. I do it too. It's a good tool but I wouldn't say it forecasts imminent component
failure - for that you look in the oil filter and if you find 10% of your camshaft in there....