Patent ID: 7874199
Filing Date: 2011-01-25
Classification: G01N

Abstract:
1. A density and viscosity sensor for measuring density and viscosity of fluid, the sensor comprising: a resonating element arranged to be immersed in the fluid, an actuating/detecting element coupled to the resonating element, a connector for coupling to the actuating/detecting element, a housing defining a chamber isolated from the fluid, the housing comprising an area of reduced thickness defining a membrane separating the chamber from the fluid, the membrane having a thickness enabling transfer of mechanical vibration between the actuating/detecting element and the resonating element, the actuating/detecting element is positioned within the chamber so as to be isolated from the fluid and mechanically coupled to the membrane, the resonating element arranged to be immersed in the fluid is mechanically coupled to the membrane, wherein the resonating element has a shape defining a first resonance mode and a second resonance mode characterized by different resonant frequencies (F