IntelliStick offers condition-based preventive maintenance by providing an onboard, real-time oil quality sensor monitoring the true condition of lube oil.

It can also detect coolant or fuel intrusion.
This provides the ability to determine, almost exactly, when it is time to change oil or add an oil additive. Preventive maintenance is thus based on real-time information rather than recommended change intervals or remote analysis.
IntelliStick's unique sensor technology was developed by Professor Robert Kauffman, an oil chemist at the University of Dayton Research Institute. Kauffman was contacted by the U.S. military to develop a sensor for use in the Joint Strike Fighter Jet and Humvee. The IntelliStick sensor, created out of this research, allows the Army to determine when to change the engine oil based on oil condition.
IntelliStick's simple and compact single electrode conductivity test applies a low voltage across two sensor arrays. The system measures the electrochemical changes caused by additive package depletion and impurities that form in the oil over time.
The sensor curve, displayed to the user through a Windows-based PDA, Smart Phone, or Laptop, indicates the remaining useful life of the engine oil. As the oil condition depletes, the IntelliStick readings begin to decline and eventually will stabilize in a flat line, which indicates that the oil is ready for change. The oil has reached its "Critical Point" when it no longer has the ability to lubricate properly. As the antioxidants deplete, the IntelliStick will detect a sharp increase of viscosity and acid number before the critical point. If the oil has passed the critical point the Kauffman Curve will begin to rise. In this case, the conductance reading increases, indicating that oil oxidation is occurring. The oil change recommendation takes place when the Kauffman Curve reading is flat, which is after the loss of additives and before oil oxidation.
For more info: www.intellistick.com