Miniature Airworthy Fiber-Optic Pressure Sensors for Measuring Static Pressure and Acoustics

Conventional electrical pressure sensors show a 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 have developed a cylindrical passive fiber-optic Fabry-Pérot pressure sensor with a diameter of 2 mm, natural frequency above 250 kHz, linear transfer characteristic, burst pressure resistance above 30 times full-scale, and without conductive and corrosive materials. It is capable of measuring aerostatics, aerodynamics and aeroacoustic events down to 60dBSPL. In combination with an industrialized edge filter interrogator, the sensor performance was successfully evaluated in two wind tunnel tests. The results pave the way to perform inflight measurements of time-resolved surface pressure measurement.