IN-LINE MONITORING OF RHEOLOGICAL PARAMETERS WITH AN ELECTROMAGNETIC FLOWMETER

Tomographic signal processing has been added to a conventional electro magnetic flowmeter. The result is a new method for measuring rheologic al parameters of viscous, non-Newtonian fluids. Tile practical realiza tion requires only minor changes lu existing instruments. Hence their main advantages are maintained, such as non-invasive. in-line measurem ent without pressure drop. The basic idea is to generate two different magnetic fields with the flowmeter by switching thr current direction in one of the magnetic coils. The flowmeter measures two signals depe nding on the flow profile. Using simple parametric models for both the flow profile and the rheology. the How profile can be calculated from the flowmeter signals, and from the flow profile the rheological beha viour is determined. The theory and experimental results with a slight ly modified industrial flowmeter are presented.