Sensor for determining mass of fluid film at boundary surface, e.g. in IC engine - has stimulated piezoelectric dual-mass vibrator protruding into boundary layer and detects change in resonant frequency

摘要

The sensor includes a stimulated piezoelectric dual-mass vibrator (3) in a housing (1) with its vibrating measurement surface (5) protruding into the boundary layer (6) and exposed to the measurement liquid. A detector (11,13,14) electrically connected to the vibrator detects its variations in resonant frequency, which are dependent on the mass of the fluid film. The vibrator contains at least two annular, piezoelectric elements arranged on either side of a carrier membrane and clamped between two inertial masses. The membrane is held between two housing parts. USE/ADVANTAGE - E.g. for use in aerodynamic and chemical applications and esp. for measuring mass of film of fuel on wall of an internal combustion engine's inlet manifold.