Vibration-type measuring transducer for conduction measurements in media flowing inside two medium lines, and on-line measuring device equipped with a measuring transducer of this type

Abstract

The measuring transmitter comprises: at least four measuring tubes (1, 2, 3, 4) for guiding the medium to be measured, each having a first and a second inlet / outlet port, during operation the measuring tubes (1, 2, 3, 4) vibrate at least intermittently, in particular simultaneously; electromechanical excitation means (60) for vibrating the measuring tube; sensor means (70) reacting at least to local vibrations of the measuring tube, for generating a vibration of at least one measured tube Measurement signal for vibration effects. Of the at least four measuring tubes, two measuring tubes (1, 2) are inserted at least intermittently into the first medium line, so that each of the two measuring tubes (1, 2) simultaneously guides flow through the first medium line medium (M 1 ) of the partial volume; and the other two measuring tubes (3, 4) of the at least four measuring tubes are inserted at least intermittently into the second medium pipe, so that each of the two measuring tubes (3, 4) simultaneously guides the flow The second medium (M 2 ) of the partial volume. Thus, on the one hand, the measuring transducer can make two media (M 1 ,M 2 ) through which the two media are measurably different in at least one physical characteristic (such as mass flow rate, media density, and / or media temperature); on the other hand, although different media (M 1 ,M 2 ), the measuring transmitter can still have good zero point stability.

Description

Technical field [0001] The present invention relates to a measuring transmitter for measuring the medium flowing in two particularly separated pipelines, and an online measuring instrument with the measuring transmitter. Background technique [0002] In order to measure or detect the process variables of the medium flowing in the pipeline, especially to detect the flow and / or rheological measurement variables, this kind of online measuring instrument is often used, which uses the vibration-type measurement variable inserted in the pipe or the shell pipeline of the guiding medium. The transmitter and the measuring and working circuit connected to it to cause reaction forces in the medium flowing through the transmitter during operation, such as Coriolis force corresponding to mass flow, inertial force corresponding to density, or viscosity Friction forces, and from these forces, a measurement signal representing the specific mass flow, viscosity and / or density of the medium is gen...

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Problems solved by technology

[0008] However, this mainly calculation-based compensation basically only eliminates the measurement errors caused by the different oscillation amplitudes, which on the one hand result in the design of the excitation device and the sensor device as well as the design of the measuring instrument electronics and the hardware for processing the measurement signal and the increased technical complexity of the software, on the other hand, the unbalance inevitably associated with the non-uniform change in the oscillation characteristics of the measuring tube can lead to significant problems with the zero point stability of the measuring transducer, which can hardly be solved by mainly limiting Compensation measures for measurement signal processing are addressed by

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