Utilizing acoustic pressure waves for sensing fluid properties

Abstract Ultrasonic sensors can be used to determine physical fluid parameters like viscosity, density, and speed of sound. In this contribution, we present the concept for an integrated sensor utilizing pressure waves to sense the bulk of the fluid. Longitudinal viscosity and speed of sound can be determined using interference effects whereas the acoustic impedance of the liquid can be sensed if interference is suppressed by introducing a wedge reflector in the setup.