Method for operating a resonance measuring system

Method for operating a resonance measuring system having at least one measuring tube with a medium flowing through it, at least one oscillation generator, at least one oscillation sensor, and at least one control and evaluation unit, comprising the steps of:

• exciting the measuring tube by the oscillation generator to oscillation with a predetermined excitation frequency and a first amplitude,
• detecting the resulting oscillation of the measuring tube with at least one oscillation sensor,
• using the control and evaluation unit to determine at least one first measured value (xi) for at least one state variable (x) that is dependent on the amplitude in a multi-phase medium,
• exciting the measuring tube by the oscillation generator to oscillation with the excitation frequency and a second amplitude which differs from the first amplitude,
• detecting the resulting oscillation of the measuring tube with the second amplitude and using the control and evaluation unit to determine at least a second measured value (xj) for the at least one state variable (x) that is dependent on the amplitude in a multi-phase medium from the determined resulting oscillation, and
• using a deviation (Δxij) of at least one of the first measured value (xi) from at least one of the corresponding second values (xj) as an indicator for the presence of a multi-phase flow.

Resonance measuring system, comprising:

• at least one measuring tube with a medium flowing through it,
• at least one oscillation generator,
• at least one oscillation sensor, and
• at least one control and evaluation unit,
• wherein the oscillation generator is adapted for exciting the measuring tube to oscillation with a predetermined excitation frequency and a first amplitude, and for exciting the measuring tube to oscillation with said predetermined excitation frequency and a second amplitude which differs from the first amplitude,
• wherein the at least one oscillation sensor is adapted for detecting oscillation of the measuring tube,
• wherein the control and evaluation unit adapted for determining at least one first measured value (xi) for at least one state variable (x) that is dependent on the amplitude in a multi-phase medium, for determining at least a second measured value (xj) for the at least one state variable (x) that is dependent on the amplitude in a multi-phase medium from the determined detected oscillations, and for using a deviation (Δxij) of at least one of the first measured value (xi) from at least one of the corresponding second values (xj) as an indicator for the presence of a multi-phase flow.