Absolute fiber optic pressure transducer for aircraft air data measurement

The authors present the design rationale for a total pressure fiber optic transducer under development for planned flight test. Pressure sealing problems for absolute pressure transduction are discussed. Information is given on the microbend fiber optic sensor approach used to measure diaphragm deflection, and requirements for microbend sensor thermal compensation. Wavelength division multiplexing (WDM) approaches are described to self-reference the fiber optic sensors so that the transducer output is insensitive to interconnect cable bending and connector mating/demating. Requirements and constraints imposed by the WDM methods are discussed, along with the impact on overall transducer operation. Preliminary performance data are presented on a prototype transducer incorporating the features necessary to achieve a stable, repeatable, and accurate output