Abstract: A pyrometer configured to sense thermal radiation within a volume (e.g., a turbomachine turbine or turbine engine) can include a photodiode configured to sense radiation at least within a desired infrared bandwidth and to output a photodiode signal, and an optical bandpass filter disposed in front of the photodiode to prevent radiation outside of the desired bandwidth from reaching the photodiode. The desired infrared bandwidth can be selected to be outside the absorption bands of one or more selected fluids such that the presence of one or more fluids (gasses) within the volume does not affect radiation that reaches the photodiode.

Abstract: Disclosed is a fuel injector for a gas turbine engine combustor that includes a fuel nozzle for injecting fuel into the gas turbine engine combustor and a fiber optic microphone operatively associated with the fuel nozzle for measuring acoustic pressure differentials within a combustion chamber of the gas turbine engine combustor. The fiber optic microphone includes a fiber bundle having at least one light transmitting fiber and one light receiving fiber; and a dynamic pressure-sensing diaphragm operatively spaced apart from a sensing end of the fiber bundle. The diaphragm has a reflective surface and is formed from a material capable of withstanding temperatures associated with flame exposure. The diaphragm is adapted and configured for deflecting in response to acoustic pressure changes within the combustion chamber.