Patent ID: 7059176
Filing Date: 2006-06-13
Classification: G01F,G01N

Abstract:
1. A viscosity sensing device comprising: a substrate; a micromachined tube supported by the substrate and comprising a fluid inlet, a fluid outlet, and a freestanding portion between the fluid inlet and the fluid outlet so as to define a continuous passage through the tube, the freestanding portion being spaced apart from a surface of the substrate; means for vibrating the freestanding portion of the tube at or near a resonant frequency thereof; means for sensing movement of the freestanding portion of the tube; and means for assessing the viscosity of a fluid within the tube by ascertaining the damping effect the fluid within the freestanding portion has on movement of the freestanding portion at or near the resonant frequency; wherein the viscosity sensing device is installed on an engine and the fluid is a lubricating oil within the engine.