The contamination factor eC is used for the calculation of life modification factor aISO. It is considering the cleanliness of the lubricant and can be calculated according to ISO 281 Annex A with the viscosity ratio, the bearing size and a selection of oil cleanness according to ISO 4406. The selection according to ISO 4406 defines how many particles of certain size may exist. The selections for grease lubrication also use ISO 281 Annex A to calculate the contamination factor eC.
In addition an own input of the contamination factor can be selected and the factor can be entered using the 
-button. The contamination factor eC is in the range from 0.1 to 1 and guide values can be selected according to (ISO 281, 2007):
Contamination level |
eC |
|
Dpw < 100mm |
Dpw ≥ 100mm |
|
Extreme cleanliness |
1 |
1 |
High cleanliness |
0.8.to 0.6 |
0.9 to 0.8 |
Normal cleanliness |
0.6 to 0.5 |
0.8 to 0.6 |
Slight contamination |
0.5 to 0.3 |
0.6 to 0.4 |
Typical contamination |
0.3 to 0.1 |
0.4 to 0.2 |
Severe contamination |
0.1 to 0 |
0.1 to 0 |
Very severe contamination |
0 |
0 |
Note that for small bearings, the values for the contamination factor eC calculated according to ISO 281 Annex A can be much lower than in the table. A user input might be preferable in this case.
