Static and Dynamic Pressure Measurement in Flight Test Application with Optical Fabry-Pérot Sensors

Conventional electrical pressure sensors show degradation of their performance in harsh environments because of their low overload protection, drawn back membrane, susceptibility to electromagnetic influences, and corrosion. Fiber-optic measurements overcome those challenges and promise to be a robust sensing solution for vigorous flight testing. We developed a passive fiber-optic Fabry-Pérot pressure sensor with a minimum thickness of 1.6 mm, natural frequency above 250 kHz, linear transfer characteristic, burst pressure resistance above >30 times full-scale, and without conductive corrosive materials. It can measure aerostatics, aerodynamics, and aeroacoustics down to 70-dB SPL. In combination with an industrialized edge filter measurement device, the fiber-optical sensor's simplified instrumentation is demonstrated on a microlight aircraft, performing dynamic maneuvers. The measurement data of near-stall flight situations demonstrate the monitoring capabilities of detached airflow in harsh environments.