Experimental characterization of the reference channel of a differential pressure sensor using pressure shock waves

This article describes the experimental verification of the hydraulic time constant related to the reference channel of a micromachined differential pressure sensor. A pressure shock wave is employed to apply a fast step impulse of large amplitude to the device under test. The impulse response of the device is captured. The hydraulic time constant of the system consisting of a channel of cross section 100×1 µm² and length 1.6 mm and a cavity of 700×700×1 µm³ is found to be about 1.2 ms. The experimental results are compared to predictions obtained by a number of analytical models and finite element simulations.