The accuracy of test results is significantly affected by the quality of the oil sample that is taken and then sent to the laboratory for processing. Temperature, humidity, wind and precipitation effects in the environment may also affect the sample quality. The location from where the sample is taken is also very important in ensuring that the sample is representative of the product being analyzed.

Sample bottles, tins or syringes should be rinsed thoroughly with the material being sampled, whilst ensuring that in doing so, no contamination from the surrounding environment is introduced into the sample.

There may be a recommended minimum volume required for certain tests (see table below) and samples taken for DGA paper degradation or furanics should also be protected from sun light.

Samples requiring trace metals and Silicon should be taken using plastic bottles for accurate results.

PCBs only	20 -100 ml	Bottle
DGA	30 - 50 ml	Syringe
Break down voltage	500 - 1000 ml	Tin, Bottle
Multiple test	min 1000 ml	Tin, Bottle
Silica	100 - 250 ml	Plastic