SBIR-STTR Award

PhotoSense, LLC proposes to design an oxygen measurement system for use in jet fuel tanks based on the selective quenching of the luminescence of certain dye molecules by oxygen. The system will require no wiring or optical paths inside the fuel tank, no heaters, will be lightweight, compact, and consume under 1 watt of power. Construction is entirely solid state, employing no liquids, valves or other moving parts. In order to calculate oxygen percentage from oxygen partial pressure, tank pressure and temperature will be measured. The unit can be constructed in a single, solid, molded package for high impact resistance, stability and ease of replacement. Each measurement includes a self-calibration to compensate for long-term drift in the electronics or optics and gives a 10 flight-year operational lifetime. The unit would require no maintenance or in-situ calibration. At the end of its life it would simply be replaced.

Benefits:
Aircraft safety in both military and commercial applications will be improved. Flight safety is a major concern in the post 9/11 world. Other commercial applications will benefit from a chemically resistant, inexpensive oxygen sensor such as in the hydrocarbon processing industry and biotechnology areas.

Keywords:
Luminescencent Oxygen Sensor, Fuel Compatibility, Automatic calibration, ullage

PhotoSense proposes to develop a ruggedized luminescent oxygen sensor compatible with aircraft fuel tanks and other harsh, flammable environments. Diverse military and commercial applications exist for an oxygen sensor operating in jet fuel and other explosive vapors over a wide range of temperatures (-65F to 140F) and pressures (2psi to 16psi) while maintaining accuracy over 10 years of use. Ignition of fuel vapor in aircraft fuel tanks has numerous times resulted in loss of life and property in commercial and military aviation. The availability of an in-tank oxygen sensor would provide feedback for more efficient use of OBIGGS, saving fuel consumption by reducing ground time waiting for tank inerting, and in flight by activating OBIGGS only when required. The in-tank oxygen sensor would also provide immediate notification of an OBIGGS malfunction, indicating the need for service. The sensor elements used materials that have been qualified for fuel and aircraft applications. The Phase II development goal is for sensors operate over temperatures from -65F to +160F for 10 years while meeting accuracy specifications of +/-0.25% (over 5% to 15% O2). The Phase II deliverable includes a prototype in-tank oxygen LUMINESCENT OXYGEN SENSOR OBIGGS FUEL INERTING JP8sensor.