Method and apparatus for determining viscoelastic properties of process fluids and its use

摘要

The invention relates to a method for determining viscoelastic properties of process fluids in a polymerization process. In the method at least one sensor head (20) is inserted in contact with a process fluid. The electric response of the sensor head (20) is measured and the viscoelastic properties of the process fluids are determined from the measured electric quantities. The invention also relates to an apparatus for determining viscoelastic properties and their changes of process fluids in a polymerization process. The apparatus is a sensor device comprising at least one sensor head (20), which comprises at least one thickness shear mode (TSM) resonator. The resonator is optionally shielded with a coating of corrosion resistant material and is fixed into the sensor head (20) with at least one elastic gasket. The apparatus also comprises a data sampling and processing unit (18) for the test signal generation and response measurement and processing.