A method of monitoring a flow behaviour of mixed components, comprising: - rotating a mixing impeller at a first speed N 1 in a mixing vessel accommodating the components to be mixed; - determining a first quantity P 1 N 1 3 at the first speed N 1, wherein N 1 is the speed at which the mixing impeller rotates and P 1 is the power required to rotate the mixing impeller at the first speed N 1; - decreasing the speed of the mixing impeller to a speed N 2; - determining a second quantity P 2 N 2 3 at the second speed N 2, wherein N 2 is the speed at which the mixing impeller rotates and P 2 is the power required to rotate the mixing impeller at the second speed N 2; - comparing the first quantity P 1 N 1 3 and the second quantity P 2 N 2 3 and detecting whether the difference between the first and second quantities is within a specified range, i.e. P 1 N 1 3 − P 2 N 2 3 ≤ T, wherein T is a predetermined or predeterminable threshold value, to determine whether the flow of the components in the mixing vessel is a turbulent flow; - determining the density ρ of the mixed components based on at least one speed N i for which the flow is determined to be turbulent by the following formula: ρ = P i N P, constant N i 3 D 5 wherein ρ is the density, P i is the power required to turn the mixing impeller at the speed N i, N P,constant is the Power number for a used mixing system configuration, N i is the speed at which the mixing impeller rotates and D is the diameter of the mixing impeller; - further decreasing the speed of the mixing impeller; - determining the Power number N P,variable for at least one detected speed N j at which the flow is determined to be non-turbulent by the following formula: N P, variable = P j ρN j 3 D 5 wherein P j is the power required to rotate the mixing impeller at the speed N j, ρ is the density previously determined based on N P,constant, N j is the speed at which the mixing impeller rotates, and D is the diameter of the mixing impeller; and - determining the dynamic viscosity μ of the mixed components by the following formula: μ = ρ 2 N j 5 D 6 x T P j wherein ρ is the calculated density, N j is the speed at which the mixing impeller rotates, D is the diameter of the mixing impeller, P j is the power required to rotate the mixing impeller at the speed N j and x T corresponds to a specified relationship between the Reynolds number for the used mixing system configuration and the determined Power number N P,variable, wherein with the specified relationship the Reynolds number N Re is replaced by x T ∗ N P. - rotating a mixing impeller at a first speed N 1 in a mixing vessel accommodating the components to be mixed; - determining a first quantity P 1 N 1 3 at the first speed N 1, wherein N 1 is the speed at which the mixing impeller rotates and P 1 is the power required to rotate the mixing impeller at the first speed N 1; - decreasing the speed of the mixing impeller to a speed N 2; - determining a second quantity P 2 N 2 3 at the second speed N 2, wherein N 2 is the speed at which the mixing impeller rotates and P 2 is the power required to rotate the mixing impeller at the second speed N 2; - comparing the first quantity P 1 N 1 3 and the second quantity P 2 N 2 3 and detecting whether the difference between the first and second quantities is within a specified range, i.e. P 1 N 1 3 − P 2 N 2 3 ≤ T, wherein T is a predetermined or predeterminable threshold value, to determine whether the flow of the components in the mixing vessel is a turbulent flow; - determining the density ρ of the mixed components based on at least one speed N i for which the flow is determined to be turbulent by the following formula: ρ = P i N P, constant N i 3 D 5 wherein ρ is the density, P i is the power required to turn the mixing impeller at the speed N i, N P,constant is the Power number for a used mixing system configuration, N i is the speed at which the mixing impeller rotates and D is the diameter of the mixing impeller; - further decreasing the speed of the mixing impeller; - determining the Power number N P,variable for at least one detected speed N j at which the flow is determined to be non-turbulent by the following formula: N P, variable = P j ρN j 3 D 5 wherein P j is the power required to rotate the mixing impeller at the speed N j, ρ is the density previously determined based on N P,constant, N j is the speed at which the mixing impeller rotates, and D is the diameter of the mixing impeller; and - determining the dynamic viscosity μ of the mixed components by the following formula: μ = ρ 2 N j 5 D 6 x T P j wherein ρ is the calculated density, N j is the speed at which the mixing impeller rotates, D is the diameter of the mixing impeller, P j is the power required to rotate the mixing impeller at the speed N j and x T corresponds to a specified relationship between the Reynolds number for the used mixing system configuration and the determined Power number N P,variable, wherein with the specified relationship the Reynolds number N Re is replaced by x T ∗ N P.