Multi-Information Monitoring of Engine Oil Degradation Using a Single Optical Sensor System

It is very important to monitor the actual condition of automobile engine oil. We propose a multi-information monitoring system of engine oil degradation for obtaining the information of the transparency, temperature and dielectric constant of the engine oil at the same time. In our research, we measure degradation extent of engine oil by using a photo-diode and Light Emitting Diode (LED). First, we measure the transparency and temperature of the engine oil by the capacitance between the two terminals of the photo-diode, second, the dielectric constant of the engine oil is measured by the capacitance between the photo-diode and outer shell of LED. Our measurement method is characterized by measuring the capacitance between two terminals of photo-diode and regarding the outer shell as an electrode of the capacitor. Experimental results show the feasibility of measuring the degradation extent of engine oil with this method.