Abstract
Degradation of oils is roughly classified into two types, one is caused by solid particles and the other is caused by oil oxidation products. Diagnosis methods for solid particles in oils have many standards and researches. However, there are few diagnosis methods for the oil oxidation products. In the present study, two themes were examined. At first, the filtration mechanism by a membrane filter was discussed using oxidized oils which were prepared in laboratory. Secondly, the transmittance of lights through the membrane patch was discussed using oxidized oils. As a result, we found that the color properties of reverse side of the membrane patch was different by the amount of the oil oxidation products, and we also found that the transmittance of lights through the membrane patch can distinguished the difference of a light color by deterioration level of the oil. They seem that these two new methods can evaluate the deterioration level of used oils. Furthermore, we developed new equipment for diagnosis of membrane patch color based on these results.
