Measurement of humid gas

FIELD: measurement equipment.SUBSTANCE: method to determine properties of a multi-phase process fluid medium includes stages, when: the multi-phase fluid medium is sent along an oscillating movable flow metering tube and a flow metre of alternating pressure difference; motion of the flow metering tube is caused, and the first apparent property of the fluid medium is determined; at least one apparent intermediate value is determined, which is the first Froude number for the non-gaseous phase of the fluid medium and the second Froude number for the gaseous phase of the fluid medium; the extent of humidity of the fluid medium is determined on the basis of conversion between the first and second Froude numbers and the extent of humidity; the second apparent property of the fluid medium is determined using the flow metre of alternating pressure difference; the phase-dependent property of the fluid medium is determined on the basis of extent of humidity and the second apparent property. At the same time the first apparent property is selected from the apparent mass flow or density. The group of inventions also relates to a flow metre comprising an oscillating movable flow metering tube, connected oscillation exciter and sensor for reading of tube motion, and a controller, and also to a metering converter of the flow metre and the system for determination of properties of the multi-phase fluid medium.EFFECT: higher accuracy for determination of properties of a multi-phase fluid medium and makes it possible to assess accuracy of operation of flow metres.21 cl, 7 dwg