Abstract: A method for determining a corrected value for a viscosity-dependent sonic velocity in a fluid under test includes generating and transmitting sound pulses to the fluid under test, registering the sound pulses after traversing a predetermined measuring distance in the fluid under test, and ascertaining a first arrival of a first sound pulse received after traversing the measuring distance and determining the transit time of the first received sound pulse in the fluid under test. A viscosity is predetermined or ascertained for the fluid under test, and a transit time of the first received sound pulse and the viscosity are used to determine the sonic velocity in the fluid under test. An apparatus for determining a corrected value for a viscosity-dependent sonic velocity in a fluid under test is also provided.

Abstract: A method and a measuring device determine the density of liquids. The measuring device has a flexural resonator, at least one sensor for at least one environmental parameter that influences a measurement to be performed and a condition monitoring unit. The measured values from the respective sensor are fed to the condition monitoring unit. The condition monitoring unit has a memory unit with stored forecasts for environmental parameters to be expected in the course of the measurement, and that, by using the condition monitoring unit, on the basis of the stored forecasts and the initial measured values selected for the measurement, it is determined whether the planned measurement can be carried out under the selected trial conditions without any impairment or with a permissible impairment by the forecast changes in the environmental parameters.

Abstract: A method and a measuring device determine the density of liquids. The measuring device has a flexural resonator, at least one sensor for at least one environmental parameter that influences a measurement to be performed and a condition monitoring unit. The measured values from the respective sensor are fed to the condition monitoring unit. The condition monitoring unit has a memory unit with stored forecasts for environmental parameters to be expected in the course of the measurement, and that, by using the condition monitoring unit, on the basis of the stored forecasts and the initial measured values selected for the measurement, it is determined whether the planned measurement can be carried out under the selected trial conditions without any impairment or with a permissible impairment by the forecast changes in the environmental parameters.

Abstract: A measuring instrument for studying fluid samples contains a flexural vibrator. A vibrator tube of which is fixed at at least one clamping position and forms on one side of the clamping position, in particular a carrier unit, a freely projecting vibrator section and on the other side a fluid feed tube section with a feed opening and a fluid discharge tube section with a fluid discharge opening. Accordingly, the vibrator tube is fixed or retained both at its fluid discharge tube section and at its fluid feed tube section with at least one independent holding device provided in addition to the clamping position.

Abstract: A method determines a degree of filling of an oscillator tube of a frequency oscillator with a fluid to be examined, in particular related to the density measurement of fluids with the frequency oscillator. By adjustment or calibration standards for the fluid to be examined, or for fluids possessing various viscosities, the relationship between the damping and/or oscillation amplitude of the frequency oscillator and the degree of filling of the oscillator tube is determined. In the course of determining the degree of filling, a parameter relevant for the damping and/or oscillation amplitude of the frequency oscillator is measured, and the measured value is considered as relevant and functionally related to the degree of filling and can be used for evaluating or determining the degree of filling.