By Jim Fitch
Practicing Oil Analysis Magazine
The best way to trend oil analysis data is to follow its movement visually using a standard trend plot. Trending can quickly reveal the rate-of-change over time (slope on the plot) associated with a series of monotonic data points that might reveal a reportable condition. It can sometimes be concluded that if the rate-of-change is normal and constant (linear trend slope) that the lubricant and machine conditions are equally normal and acceptable. However, abnormal or unhealthy conditions do not aways produce steep trend lines.