Patent ID: 7207210

Claim:
Method for measuring a physical property of a fluid undergoing a state change, comprising the steps of: (a) providing a rotary viscometer instrument having a rotor assembly including a spindle, a chamber in which the fluid is to be contained, means for adjustably driving the rotor assembly, means for measuring torque imparted to the spindle and converting the measured torque to a viscosity measurement; (b) placing a fluid to be tested in the chamber; (c) placing the spindle in contact with the fluid; (d) rotating the rotor assembly at a constant rotational speed; (e) measuring torque imparted to the spindle by the fluid and converting the measured torque to a viscosity measurement until at least one torque set point is reached; (f) determining if at least one process parameter has reached a predefined end point, and if the at least one process parameter has not reached the end point, dynamically changing the rotational speed of the rotor assembly to a different constant speed; and (g) repeating steps (e) and (f) until the at least one process parameter reaches the predefined end point.