Providing Embedded, In-situ Oil Quality Monitoring for Improved Maintenance and On-Board Diagnostics in Trucking and Automotive Applications

This paper presents the development of a fluid quality sensor to provide a real-time, on-board oil quality assessment capability for commercial, military, and off-highway vehicle applications. The sensor provides for improved vehicle health state awareness and enables a condition-based approach to lubricant maintenance. The technology is based on a broadband approach to electrochemical impedance spectroscopy (EIS) and is applicable to all high impedance fluids. The EIS results are fused with the measurements from a capacitive relative humidity sensing element and are normalized with respect to temperature as measured by an embedded thermistor. The authors' experiences in developing, packaging, and testing this technology are chronicled.