Are you developing new methods or applications in instrumental analytics or material characterization? Then you have the chance to win this prestigious award with a monetary prize of € 20,000.Find out more
Examples of a flow curve and viscosity curve
Typical examples for ideally viscous, Newtonian liquids are water, mineral oil, silicone oil, salad oil, solvents such as acetone, as well as viscosity standards (e.g. calibration oils).
Water shows a constant viscosity of η = 1 mPas, which is ideally viscous behavior (Figure 1). The presentation in the diagram was limited to a shear-rate range of between 0.2 s-1 and 200 s-1. Mineral oil and silicone oil show similar behavior (Figures 2 and 3).
At lower shear rates, the detectable torque signal would be too small under these measuring conditions. At higher shear rates, turbulent flow effects in the gap would cause disturbances to the flow. There is no way of preventing such effects when testing fast-flowing low-viscosity liquids. In this case, the requirements for a scientifically precise calculation of the viscosity would not be met because the precondition is laminar flow.