Patent ID: 7752895

Claim:
A method for screening or determining a variation in viscosity of a fluid, the method comprising: a) providing a fluid sample to a reservoir placed in a thermostatic control system; b) placing a capillary in fluid communication with the fluid sample, wherein the capillary has a first end and a second end with a substantially uniform diameter over a predetermined length, the first end being submerged in the fluid sample to be measured, the second end attached to a manifold having at least one selectable valve, the capillary together with the manifold and the at least one selectable valve define a chamber of predetermined volume; c) actuating at least one selectable valve attached to the manifold to allow an oxidative gas to enter into and pass through the manifold and capillary; d) inducing the sample into the capillary by rapidly generating a dynamic differential pressure in the chamber thus allowing the sample to flow from the reservoir through the capillary; e) detecting pressure change of the chamber as a result of the fluid flow; and f) relating the rate of pressure change to the variation in viscosity.