Fiber optic total-pressure transducer for aircraft applications

We have completed development of a temperature compensated, self-referenced, microbend fiber optic pressure transducer for total pressure measurement. This transducer outputs the sum of altitude dependent background pressure and dynamic pressure proportional to air speed. During planned flight tests, the fiber optic pressure transducer will be installed in the same pitot pressure line as the present electronic pressure transducer, so that simultaneous data from the two transducers can be collected for subsequent analysis and comparison. Design information and design trade-offs for fiber optic total pressure measurement are presented in this paper. Methods to make pressure seals to achieve absolute pressure transduction are discussed. Information is provided on microbend fiber optic sensor design and thermal compensation. The approach used for wavelength division self-referencing is described to make the transducer output insensitive to link cable bending and connector mating/demating. Pressure calibration data is presented.