Coriolis mass flow measuring device

Abstract

A Coriolis mass flow measuring device comprises a measuring device electronics as well as, connected thereto, a measuring transducer comprising at least one measuring tube, an oscillation exciter for oscillating the at least one measuring tube and, mutually spaced along the measuring tube, two oscillation sensors for generating oscillation signals representing oscillations of the measuring tube. The measuring tube is adapted to be flowed through by a medium and during that to be caused to vibrate in such a manner that the measuring tube executes wanted oscillations having a wanted frequency. The wanted oscillations are suitable to induce in the flowing medium, dependent on its mass flow rate, Coriolis forces suitable for bringing about a measurement effect of a first type, namely Coriolis oscillations of the wanted frequency superimposed on the wanted oscillations. These Coriolis oscillations are, in turn, suitable to induce in the medium centrifugal forces dependent on its mass flow rate and on its density. These centrifugal forces bring about a measurement effect of a second type, namely, superimposed on the Coriolis oscillations, centrifugal oscillations of the wanted frequency. The measuring device electronics is, among other things, adapted, based on the oscillation signals, to generate at least one mass flow, measured value, representing the mass flow rate, in such a manner that a dependence of a phase difference existing between wanted signal components of the oscillation signals is taken into consideration by the measurement effect of second type.