Patent ID: 7874208
Filing Date: 2011-01-25
Classification: G01F,G05D

Abstract:
1. A flow measuring device comprising: a housing with a fluid inlet and a fluid outlet; a main flow path fluidly coupled between the inlet and the outlet; a pressure dropping bypass disposed in the main flow path; a flow sensor conduit fluidly coupled between the inlet and the outlet and disposed in parallel with the pressure dropping bypass, said flow sensor conduit providing a sensor flow path from an inlet of the flow sensor conduit to an outlet of the flow sensor conduit; a flow sensor configured to sense a fluid flow of the fluid through the flow sensor conduit; and at least one restriction disposed in the sensor flow path where the restriction provides a non-linear relationship between a pressure drop across the sensor flow path and the fluid flow through the flow sensor conduit, the at least one restriction comprises an outer portion formed from a material and an orifice passing through the material, wherein the orifice is sized to provide the pressure drop, at a flow corresponding to a full scale sensor output, which is greater than a non-restriction pressure drop within the flow sensor conduit alone at said flow.