Patent ID: 6571608
Filing Date: 2003-06-03
Classification: A61B,G01N

Abstract:
A method for determining the online viscosity of a fluid flowing through a process, said method comprising the steps of:(a) providing a lumen having a first end and a second end, said first end being coupled to the process through a valve and wherein said lumen is positioned at an angle to a horizontal reference greater than zero degrees, said lumen having a first known dimension; (b) coupling an inlet of a flow restrictor, having an outlet, to said second end of said lumen, said flow restrictor having some known dimensions; (c) disposing a collector on a weight detector and positioning said outlet to deliver any fluid flowing through said outlet into said collector; (d) opening said valve to allow a predetermined amount of fluid from the process to pass through said lumen and said flow restrictor and to collect in said collector to submerge said outlet and to form a continuous sample of fluid occupying said lumen and said flow restrictor, said opening of said valve establishing a pressure differential between said first end and said outlet; (e) obtaining an initial weight of said collector by said weight detector; (f) further controlling said valve to vent said first end to atmospheric pressure to cause said sample of fluid to move through said lumen and said flow restrictor at a first shear rate caused by said pressure differential, said movement of fluid causing said pressure differential to decrease from said first shear rate for generating said plural shear rates; (g) detecting the changing weight of said collector over time as said sample of fluid passes through said outlet into said collector while maintaining said outlet being submerged in the fluid in said collector; and (h) calculating the online viscosity of the fluid based on the changing weight of said collector over time, said first known dimension and said some known dimensions.