Multi-decade viscometric or rheologic measurements of a material undergoing state change

Method for measuring a physical property of a fluid undergoing a state change that may include a viscometric or rheologic property, 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.