Truck in harsh conditions

White Paper

FPS2800 Oil property sensor for engine condition monitoring

This White Paper document presents the algorithm design to monitor engine condition.


The FPS2800 oil property sensor from TE Connectivity, predicts remaining oil life and inducing oil change interval optimization, minimization of dramatic engine failure and maintenance costs reduction. After a general description of the sensor measurement principle, the different engine oil contaminations and ageing phenomena and the associated sensor detection and measurements capabilities, the general oil condition algorithm strategy on the FPS2800 sensor is detailed and supported by state of the art references.

To optimize oil quality and induced engine efficiency, engine and oil manufacturers usually recommend an oil change interval in months or hours of operation, which is dependent of each specific application. Oil quality is generally monitored externally with punctual samplings analyzed in dedicated laboratories. External monitoring has several disadvantages. First external monitoring is not able to detect rapid oil contamination or quality changes that could induce dramatic engine and system failures. Secondly, the manufacturers choose to recommend restrictive oil change intervals to decrease failure risks. This solution causes high maintenance costs and oil waste.


The internal engine oil condition monitoring with the TE Connectivity FPS2800 sensor definitively allows a simplification of oil quality management, a higher capability detection of slow and rapid oil contamination or quality and an economic and environmental friendly optimization of oil change intervals.


Although this paper demonstrates oil condition algorithm feasibility, presented models and analysis are highly dependent on oil type and application characteristics. Specific studies should then be performed before implementation in each application to adapt and optimize the described models.

Fluid sensor


The TE Connectivity FPS2800 sensor directly and simultaneously measures the viscosity, density, dielectric constant and temperature of non-conductive oil. Relying on tuning fork technology, the sensor monitors the direct and dynamic relationship between multiple physical properties to determine the quality, condition and contaminant loading of fluids such as engine oil, fuel, transmission and brake fluid, hydraulic and gear oils, refrigerants and solvents. The multi-parametric analysis capability improves fluid characterization algorithms. The FPS2800 sensor provides in-line monitoring of fluids for a wide range of OEM and aftermarket installations including fluid reservoirs, process lines and pressurized high flow conduits (e.g., engine oil gallery) for applications that include on and off highway vehicles, HVAC&R, compressors, industrial equipment and turbines. This paper will focus principally on the engine oil application but most of analysis can be adapted or replicated for other applications.