Direct Bandwidth Measurement of Dynamic Pressure Sensors

We present an experimental method for performing direct, high-speed dynamic pressure measurements of MEMS-based sensors with bandwidths exceeding 1 MHz. A focused nanosecond-pulsed laser beam is used to generate a laser-induced spark, which rapidly expands into a supersonic shock wave that excites the pressure transducer. A windowed chamber with an integrated heating element enables characterization of the sensor's dynamic pressure response at temperatures ranging from 25°C to 1000°C. A precision PID-controlled pressure regulation system is employed to establish static pressure setpoints from 1 Pa to 33,000 Pa (absolute), which are then dynamically modulated by the laser-induced shock wave. This method offers significant advantages in repeatability, accuracy, and bandwidth compared to other direct and indirect measurement techniques, such as shock tubes, ultrasonic excitation, or low-frequency reciprocal calibration.