Evaluation of engine oil degradation based on viscosity and transmitted light intensity measurements

Most methods that are used to evaluate the performance degradation of engine oil require considerable amounts of the engine oil. Hence, novel techniques that require only small amounts of samples are needed. In this study, we investigated the feasibility of using the viscosity of and the intensity of light transmitted from a small amount of engine oil to evaluate the degradation of the oil. The viscosity was measured through repeated evaluations of the flow conditions using a fine capillary tube. The light intensity transmitted through the sample oil was measured using a light-emitting diode and photodiode. Using the two evaluation methods, we analyzed six oil samples that had undergone different durations of usage. Subsequently, the correlation between the durations and measured values was examined. The results indicated that the viscosity and light intensity decreased with increase in the duration of usage. From these results, we found that our viscosity and transmitted light intensity measurement methods could be used to evaluate the degradation of engine oil using small amounts of the oil. In addition, the transmitted light intensity can be used to estimate turbidity.

Automated summary

In this study, the feasibility of using the viscosity and light intensity of a small amount of engine oil to evaluate its degradation was investigated. The viscosity was measured using a fine capillary tube, and the light intensity was measured using a light-emitting diode and photodiode. The results showed that both the viscosity and light intensity decreased with increasing duration of usage, indicating that these methods can be used to evaluate the degradation of engine oil using small amounts of samples.