Cyclic polymer processing method including an inline viscosity measurement method

A cyclic polymer processing method comprising an inline viscosity measurement method for determining a viscosity measurement value of a fluid polymer stream, wherein the fluid polymer stream flows through a measuring section arranged in a closed channel, wherein the closed channel comprises a longitudinal axis, an inlet end and an outlet end, wherein the measuring section extends at least between the inlet end and the outlet end, wherein a static mixer is arranged in the measuring section, which contains at least one built-in element, wherein an inlet pressure upstream of the at least one built-in element is measured by an inlet pressure sensor so that an inlet pressure measurement value is obtained, and wherein an outlet pressure downstream of the at least one built-in element is measured by an outlet pressure sensor so that an outlet pressure measurement value is obtained, wherein the inlet pressure measurement value and the outlet pressure measurement value are converted by means of a transducer into measurement variables that can be processed by a computer unit, wherein the computer unit determines a pressure difference between the inlet pressure measurement value and the outlet pressure measurement value, wherein a flow rate of the fluid polymer stream is determined via a conveying device or a flow rate measuring device, wherein the viscosity measurement value is determined from the pressure difference of the fluid polymer stream and the flow rate of the fluid polymer stream by means of a calculation formula, wherein the fluid polymer stream is not a side stream with recirculation, so that the fluid polymer stream is mixed by means of the static mixer, wherein a maximum measured pressure difference during a measurement time per cycle is at least 5 bar.