Method for determining the filling quality of an oscillator, the oscillator tube of which is flowed through by a measurement fluid to be examined, - wherein an adjustment curve or adjustment table is used which provides the functional connection between a parameter significant for the damping of the oscillator tube and the dynamic viscosity of measurement fluids, wherein, in order to create an adjustment curve or adjustment table, measurement fluids with known dynamic viscosity are used as adjustment standards and the connection between the dynamic viscosity of the measurement fluid and a parameter significant for the damping of the oscillator tube, preferably the amplitude and/or phase of a natural vibration, is determined, - wherein, in order to determine the filling quality, in the course of the measurement of the measurement fluid with the oscillator using an autonomous, further or additional measurement device, at least one measurement value is specified for the dynamic viscosity of the measurement fluid to be examined, - wherein in the course of the measurement of the measurement fluid to be examined with the oscillator at least one measurement value is specified for the parameter, significant for the damping of the oscillator tube, said parameter being preferably the density of the measurement fluid to be examined, - wherein the obtained measurement value for the dynamic viscosity of the measurement fluid to be examined on the adjustment curve or in the adjustment table is assigned a conditional or a specific function value of the parameter significant for the damping of the oscillator tube and a comparison of the assigned function value with the obtained measurement value for the parameter significant for the damping of the oscillator tube is carried out, and - wherein the result of this comparison is evaluated with regard to the possible presence of a filling error or is used to determine a possible filling error of the oscillator. - wherein an adjustment curve or adjustment table is used which provides the functional connection between a parameter significant for the damping of the oscillator tube and the dynamic viscosity of measurement fluids, wherein, in order to create an adjustment curve or adjustment table, measurement fluids with known dynamic viscosity are used as adjustment standards and the connection between the dynamic viscosity of the measurement fluid and a parameter significant for the damping of the oscillator tube, preferably the amplitude and/or phase of a natural vibration, is determined, - wherein, in order to determine the filling quality, in the course of the measurement of the measurement fluid with the oscillator using an autonomous, further or additional measurement device, at least one measurement value is specified for the dynamic viscosity of the measurement fluid to be examined, - wherein in the course of the measurement of the measurement fluid to be examined with the oscillator at least one measurement value is specified for the parameter, significant for the damping of the oscillator tube, said parameter being preferably the density of the measurement fluid to be examined, - wherein the obtained measurement value for the dynamic viscosity of the measurement fluid to be examined on the adjustment curve or in the adjustment table is assigned a conditional or a specific function value of the parameter significant for the damping of the oscillator tube and a comparison of the assigned function value with the obtained measurement value for the parameter significant for the damping of the oscillator tube is carried out, and - wherein the result of this comparison is evaluated with regard to the possible presence of a filling error or is used to determine a possible filling error of the oscillator.