Oxygen Sensor for Aircraft Fuel Inerting Systems

U. S. Patent 7,352,464

Apparatus for measuring oxygen for fuel tanks.

Aircraft fuel tanks contain both liquid fuel and a gaseous mixture of fuel vapors and air. The gaseous part is refered to as "ullage." With the right concentration of fuel and oxygen, the gas mixture can be explosive. To prevent accidents, air can be replaced with an inert gas that contains no oxygen, a process known as "inerting." A well-designed system needs some method of verifying that the oxygen has been removed and the gas in the fuel tank is safe. Challenges include sloshing of the liquid fuel and the change in fuel level and temperature over the flight cycle. Naturally, the oxygen measurement system should not pose any additional hazards such as electrical wiring within the tank.

This patent describes an invention that allows optical measurements to be made in the ullage space. The approach is inherently safe: a low-power beam of light, even weaker than a laser pointer, passes through the gas mixture. No electronics contact the vapor so there is no danger of sparks. The invention allows oxygen to move in and out of the measurement region without allowing fuel to splash on optical surfaces, which otherwise would limit performance.

Contact Information