Particle rating in ferrography

There aren't any written rules. Each company has developed its own normal-to-critical rating system. Then, it's up to the individual interpreting the ferrogram to assign the rating they feel is most appropriate for the particles in question.

If you're looking for a systematic training reference for ferrography, try the Wear Particle Atlas CD-ROM from Lubrosoft.

Mark Smith
Analysts, Inc.

How do you rate the particles in your company? Is it by the percentage of the ferrogram covered by particles? And do you use dilutions? As about the CD, I have it but I don´t have the operating key to open the program. Contacting lubrosoft hasn´t made any result. Thanks

I have some difficulty in distinguishing sand particles from lube degradation. I see aglomerated particles envolving the rubbing wear which are translucid and by polarized light are not shinning but not dark neither. What do you think? I can provide some pictures.

particle rating in analytical ferrography is purely based on subjective scale severity index these index could be determined by using type of machine being monitored, quantitative results, size of the particles, concentration & orientation of the particles, composition & surafce structure of the particles. each has significant contribution size & concentration will give severity of wear. surface structue & composition will give source and some times root cause of wear.
sensitivity of the equipment plays key role in deciding the severity scale. gear boxes(high speed rough running) have different strategy when campared to clean running sensitive turbines.