Store the sealing ring: When opening the sampling nozzle, the sealing ring may get lost when the safety cap is unscrewed. It must remain on the nozzle.

Avoid air bubbles: Take the sample using a device with an inspection window. This ensures any air bubbles are detected. Air bubbles can distort the oil sample. This device is first screwed onto the nozzle. 

Rinsing the sample bottle: The sample bottle (already cleaned and dried) is then filled with oil, placed on its side and swivelled or rotated so that the oil dampens the entirety of the wall surface and absorbs any remaining dirt particles. The oil used for rinsing the bottle must then be poured out and disposed of properly at a later point.

Taking samples: For the actual sampling, the tube connected to the sampling nozzle should reach to the bottom of the sample container. The bottle is slowly filled to avoid bubbles until it overflows. Up to 50 % of the bottle's contents may overflow. This produces a homogeneous sample without any pockets of air. The overflowing oil needs to be collected, e.g. in a bucket, and disposed of properly. 

Close the bottle: After filling the bottle, make sure it has an airtight seal by using the screw cap. The bottle needs to be filled to the brim with oil so that no air remains in the bottle neck. After sealing, the bottle can be cleaned, packed and the excess oil can be disposed of.