Method and device for non-invasively determining properties of a multiphase flow

A method for non-invasively determining properties of a multiphase flow which comprises a liquid fraction and a gaseous fraction and flows through an electrically conductive object, the method using a single set-up having a plurality of EMAT transducers, the method comprising the steps of:

• determining the velocity of the gaseous fraction by spatially correlating at least two signals with one another;
• determining the velocity of the liquid fraction by evaluating:
• at least one signal arising on the basis of a wave reflected from a reflection source in the multiphase flow, or
• at least one signal arising on the basis of a wave transmitted upstream and coupled at least into a part of the multiphase flow and at least one signal arising on the basis of a wave transmitted downstream and coupled at least into a part of the multiphase flow;
• and
• determining at least one of the flow cross-section fraction of the gaseous fraction and the flow cross-section fraction of the liquid fraction by evaluating:
• at least one signal arising on the basis of a wave transmitted downstream or upstream and coupled at least into a part of the multiphase flow, or
• at least one signal arising on the basis of a part of a wave transmitted downstream or upstream, said part propagating exclusively in the object wall.