Electromagnetic in-line measurement of viscosity

Continuous viscosity measurement assists in product quality procurement and maximizes the efficiency of plant operation. However, state-of-the-art commercial instruments have severe drawbacks such as using by-pass loops or being invasive. Based on a conventional electromagnetic flowmeter, a noninvasive process viscometer has been developed Through slight modifications of a commercial flowmeter two measured quantities related to the velocity profile can be determined Emerging from a two-parametric rheological model as a theoretical background, the complete velocity profile can be approximated An additional differential pressure sensor provides a third rheological parameter so that the viscosity can be obtained The key features of the inline process viscometer are no moving parts, ease of cleaning, no dead zones and no additional pressure loss. A prototype of the proposed viscometer has been constructed and extensively tested with various fluids. The results underline the good performance of the measuring principle.