Improper Oil Sampling Procedures
The greatest hindrance to a successful oil analysis program is improper oil sampling procedures. Failure to follow the recommendations in this chapter will make the oil analysis program cost more time and money and lower its effectiveness. Re-sampling requirements incur labor and financial costs. Re-sampling also delays lab results, which may indicate the need for critical action, and increases the potential for unnecessary equipment wear increases as maintenance lags. Finally, improperly taken samples may indicate the need for filter or fluid changes when none are necessary.
The following common problems may lead to a skewed oil sample:
- Dirty hands, gloves or sampling valve

- Dirty atmosphere when sample was taken.
- Sampling bottle lid left off for extended period of time allowing airborne contaminants and moisture to enter bottle
- Sampling equipment while it is not running
- Sampling before equipment has run long enough to reach operational temperature
- Not purging the sampling valve
- Taking the sample from purged oil