Method For Determining The Mass Flow Through A Coriolis Mass Flowmeter

Abstract

To ascertain the mass-flow of a Coriolis mass-flow meter, an oscillation of a measuring tube is produced with the frequency f and the resulting oscillatory movement is registered at two different measuring points with two oscillation sensors. The analog sensor signals X17, X18 of the two oscillation sensors are converted into digital sensor signals S1 and S2 and further processed in a digital signal processor DSP. In the signal processor DSP, the sum signal Σ and the difference signal Δ are formed from the two sensor signals S1 and S2. Then the sum signal is rotated by 90°. In a further method step, the shifted sum signal is multiplied with the difference signal Δ. After ascertaining the amplitude of the sum signal Σ, the mass-flow is ascertained using the formula {dot over (m)}˜|Im(Δ)|/(|Σ|f). It is not necessary for the method, that the two sensor signals S1, S2 have equal amplitudes. Thus, a controlling of the analog signals X17, X18 to equal amplitudes can be omitted.

Dependencies are inferred from the claim text.