Patent ID: 7878044

Claim:
A method of measuring at least two fluid properties selected from density, viscosity, and elastic modulus, when the third of said fluid properties is known or assumed, the method comprising the steps of: providing a Multi Mode Quasi Shear Horizontal Resonator (MMQSHR) having an energy input, and a measuring surface for contacting said fluid, said measuring surface having at least a first region and a second region, and a separation area defined therebetween; feeding said MMQSHR with excitation energy via said input, at a first frequency and then at a second frequencies selected to excite a first and a second acoustic modes respectively, each of said acoustic modes causing a component of horizontal shear wave motion in said surface, wherein excitation in said first frequency further causing said regions to move in phase relative to each other; and wherein excitation in said second frequency causes said two regions to move out-of-phase relative to each other, inducing a vertical displacement in said separation area; measuring energy related parameters at said first mode and second mode; calculating two of said fluid properties utilizing said energy related parameters and information relating to said third fluid property.