Easy. Look at the parts per million, or ppm for short, count on the sample report. When you get an oil sample it will list all the metals and their ppm if applicable. When you keep sampling the same compartment, eg. engine, you will see a trend with the ppm either going up or down. Normally, depending on how frequently you sample, you will see a high ish reading of your wear metals for the first couple of samples if the compartment is new or rebuilt. This is due to running in of components inside the compartment. After a while the ppm count should drop. If it rises there may be a problem that needs looking into. When I get some time I'll post a copy of my oil sample report and that should explain it a bit clearer.