Abstract: A flow meter obtains the individual flow rates of gas, liquid hydrocarbons, and water in a predominantly gas-containing flowing fluid mixture. The flow meter comprises a water content meter (7) provides a signal representing a measure of the water content of said fluid. It also comprises a double differential pressure generating (3) and measuring (4) structure, denoted a DDP-unit (2), that provides two measurement signals (6A and 6B) representing two independent values of differential pressure (DP) in said fluid (1). In addition to the above, the meter also comprises a signal processing unit (8) having inputs (9A-C) for receiving the measurement signals and the water content signal, and a calculation module (10) which calculates values representing the volumetric flow rates of said gas, liquid hydrocarbons and water in said fluid.

Abstract: Apparatus for measuring the composition and flow rate of a fluid (1) comprising a mixture of e.g. oil and water in a pipe (2), wherein an integrated mechanical structure (3) serves as a microwave resonator sensor for providing permittivity measurements and where the mechanical structure also functions as a differential pressure element for providing flow rate measurements.

Abstract: Apparatus for measuring the composition and flow rate of a fluid (1) comprising a mixture of e.g. oil and water in a pipe (2), wherein an integrated mechanical structure (3) serves as a microwave resonator sensor for providing permittivity measurements and where the mechanical structure also functions as a differential pressure element for providing flow rate measurements.

Abstract: A method for measuring properties of a flowing fluid composition comprising at least two different components, while the fluid composition is flowing through a duct or channel, which flow meter comprises: at least one sensor (2, 3) in the shape of a cavity resonator through which at least a portion of the fluid composition passes; at least one electronic circuit (4) comprising a transmitting means (11) adapted to transmit an electronic signal (9) into the flowing fluid via a probe (7, 11); at least one receiving means adapted to receive a signal which has traveled through the flowing fluid composition; and at least one signal processing unit (12) adapted to deduce fluid specific signals from the received signals. An oscillator included in the electronic unit (4) may, in a preferred embodiment, be phase locked to the resonant frequency of the sensor (2, 3) (in a so-called FSA (feedback self-oscillating amplification) method).

Abstract: A method for measuring properties of a flowing fluid composition comprising at least two different components, while the fluid composition is flowing through a duct or channel, which flow meter comprises: at least one sensor (2, 3) in the shape of a cavity resonator through which at least a portion of the fluid composition passes; at least one electronic circuit (4) comprising a transmitting means (11) adapted to transmit an electronic signal (9) into the flowing fluid via a probe (7, 11); at least one receiving means adapted to receive a signal which has traveled through the flowing fluid composition; and at least one signal processing unit (12) adapted to deduce fluid specific signals from the received signals. An oscillator included in the electronic unit (4) may, in a preferred embodiment, be phase locked to the resonant frequency of the sensor (2, 3) (in a so-called FSA (feedback self-oscillating amplification) method).

Abstract: A microwave sensor (3) for measuring the relative proportions of fluids is provided. The sensor (3) includes a tube (4) having a length (9) for accommodating the fluids flowing through said tube. The length (9) of the tube (4) makes up a part of the sensor (3). Also included are probes (6, 7) for transmitting electromagnetic energy into the sensor (3) and receiving electromagnetic energy from the sensor (3). The sensor (3) uses resonance at a resonant frequency (fm) below the cut-off frequency (fm) of the tube (4). The tube (4) includes at least one radially extending, conducting, internal fin (5) extending along the axis (10) of the tube (4). The fin (5) may be of regular or irregular shape and may be fixedly or detachedly arranged, e.g., through a slot (13).