MASS FLOW METER ON THE CORIOLIS PRINCIPLE

A mass flow meter on the Coriolis principle comprises two parallel straight measuring tubes (2, 3). An oscillator (11) drives the measuring tubes in opposite senses at a fundamental oscillation and a superimposed harmonic. Sensors (14, 15) receive measuring signals from which an uncorrected mass flow (Q1) is derived. A frequency determining circuit (30) determines from a measuring signal (U1) the values of the resonance frequencies (f1, f3) of the fundamental oscillation and harmonic for the purpose of deriving therefrom a correcting value (k) which takes axial stresses in the measuring tubes (2, 3) into account to determine a corrected mass flow (Q2). In this way, a mass flow meter can be made which has slight lateral deflection and gives accurate measuring results despite the occurrence of axial stresses. Fig.1