Endress + Hauser Flowtec Ag

Ibho Itin

Alfred Rieder

Wolfgang Drahm

Michael Fuchs

Hans-Jörg Sprich

Samuel Wyss

A Coriolis mass flow measuring device includes a vibratory measuring transducer having at least one measuring tube, which has medium flowing through it during operation. In operation, the measuring tube is caused by an exciter arrangement to undergo mechanical oscillations, especially bending oscillations. Additionally, the Coriolis mass flow measuring device includes a sensor arrangement for producing oscillation measurement signals (s, s) representing the inlet-end and outlet-end oscillations of the measuring tube. Measuring device electronics controlling the exciter arrangement produces an exciter current (i) and an intermediate value (X') derived from the oscillation measurement signals (s, s). This intermediate value represents an uncorrected mass flow. Derived from the exciter current and/or from a component of the exciter current (i), an intermediate value (X) is produced, which corresponds to a damping of the oscillations of the measuring tube. This damping is especially a function of an apparent viscosity, and/or a viscosity-density product, of the medium guided in the measuring tube. Furthermore, a correction value (X) is produced for the intermediate value (X&#x2032;) utilizing the intermediate value (X) and a viscosity measurement value (X) determined initially or during operation. The viscosity measurement value (X) corresponds to a viscosity of the medium guided in the measuring tube and/or to a predetermined reference viscosity. On the basis of the intermediate value (X&#x2032;) and the correction value (X), the measuring device electronics then produces an exact mass flow rate measurement value (X).

Coriolis mass measuring device

An inline measuring device includes a vibration-type measurement pickup having at least one measuring tube, which has a medium to be measured flowing through it during operation. The measuring tube is made by means of an exciter arrangement to execute, at least at times and/or at least in part, lateral oscillations and, at least at times and/or at least in part, torsional oscillations about an imaginary measuring tube longitudinal axis. The torsional oscillations alternate with the lateral oscillations or are, at times, superimposed thereon. Also included is a sensor arrangement for producing oscillation measurement signals correspondingly representing oscillations of the measuring tube. Measuring device electronics controlling the exciter arrangement generates, by means of at least one of the oscillation measurement signals and/or by means of the exciter current, at least at times, at least one measured value, which represents the at least one physical quantity to be measured. Additionally, the measuring device electronics also determines a first intermediate value, which corresponds to the lateral current component of the exciter current serving to maintain the lateral oscillations of the measuring tube and/or to a damping of the lateral oscillations of the measuring tube, as well as a second intermediate value, which corresponds to a torsional current component of the exciter current serving to maintain the torsional oscillations of the measuring tube and/or to a damping of the torsional oscillations of the measuring tube. With the goal of producing the measured value at high accuracy, such value is determined also taking into consideration these two intermediate values. The measured value obtained in this way is distinguished especially by high accuracy also in the case of media of two, or more, phases.

In-line measuring device

A Coriolis mass flow measuring device includes a vibratory measuring transducer having at least one measuring tube, which has medium flowing through it during operation. In operation, the measuring tube is caused by an exciter arrangement to undergo mechanical oscillations, especially bending oscillations. Additionally, the Coriolis mass flow measuring device includes a sensor arrangement for producing oscillation measurement signals (s, S) representing the inlet-end and outlet-end oscillations of the measuring tube. Measuring device electronics controlling the exciter arrangement produces an exciter current (i) and an intermediate value (X') derived from the oscillation measurement signals (s, s). This intermediate value represents an uncorrected mass flow. Derived from the exciter current and/or from a component of the exciter current (i), an intermediate value (X) is produced, which corresponds to a damping of the oscillations of the measuring tube. This damping is especially a function of an apparent viscosity, and/or a viscosity-density product, of the medium guided in the measuring tube. Furthermore, a correction value (X) is produced for the intermediate value (X&#x2032;) utilizing the intermediate value (X) and a viscosity measurement value (X) determined initially or during operation. The viscosity measurement value (X) corresponds to a viscosity of the medium guided in the measuring tube and/or to a predetermined reference viscosity. On the basis of the intermediate value (X&#x2032;) and the correction value (X), the measuring device electronics then produces an exact mass flow rate measurement value (X).

Growing community of inventors

Liestal, Switzerland

Ibho Itin