DUAL PURPOSE FIBER OPTIC SENSOR FOR MONITORING AIRCRAFT OXYGEN SYSTEMS

THE ABILITY OF CREWMEMBERS TO OPERATE EFFECTIVELY AND SAFELY IS CONTIN UOUSLY BEING TESTED AS AEROSPACE VEHICLES ATTAIN FASTER SPEEDS, HIGHER ALTITUDES, AND HIGHER G ENVIRONMENTS. THE CREWMEMBERS' BREATHING APPARATUS OR MOLECULAR SIEVE OXYGEN GENERATING SYSTEM (MSOGS) IS OF PRIMARY IMPORTANCE. HOWEVER, NO SENSORS ARE AVAILABLE THAT CAN MEASURE OXYGEN CONCENTRATION AND FLOW RATE SAFELY, BETWEEN THE REGULATOR AND THE CREWMEMBER'S MASK, IN A FLIGHT TEST ENVIRONMENT. WE PROPOSE A FIBER OPTIC SENSOR THAT CAN MEASURE BOTH OXYGEN CONCENTRATION AND FLOW RATE SAFELY AND RELIABLY. THE PROPOSED OXYGEN CONCENTRATION SENSOR UTILIZES POROUS OPTICAL FIBERS AND GAS SPECIFIC INDICATOR DYES. THE PROPOSED FLOW RATE SENSOR USES A LENGTH OF COMMERICALLY AVAILABLE FIBER HELD TAU GHT ACROSS THE GAS FLOW. VIBRATIONS INDUCED IN THE OPTICAL FIBER, WHICH ARE DIRECTLY RELATED TO THE FLOW RATE, ARE MONITORED OPTICALLY VIA A CHANGE IN SPECKLE PATTERN, OR INTERFEROMETRICALLY. A PHASE II PROTOTYPE WOULD INVOLVE COMBINING BOTH OF THESE SENSING TECHNIQUES INTO A SINGLE OPTICAL FIBER SENSOR.