Abstract: A method for use in measuring a composition of a multiphase fluid which includes flowing a multiphase fluid through a fluid flow path defined by a wall of a fluid conduit is disclosed. The wall includes an electrically non-conductive material. The method includes establishing an electromagnetic field which extends through the electrically non-conductive material of the wall of the fluid conduit into the fluid and measuring a property of the electromagnetic field over a measurement time period. The method also includes transmitting additional energy through the fluid over the measurement time period independently of the electromagnetic field and measuring the additional energy transmitted through the fluid over the measurement time period. The method may be used to unambiguously determine a composition of a multiphase fluid which has different components.

Abstract: An apparatus for measuring a composition of a fluid has a fluid conduit with a wall defining a fluid flow path, a transmitting antenna, a receiving antenna, and an electrically conductive waveguide member for electromagnetic coupling with the transmitting antenna and the receiving antenna and for guiding an electromagnetic field from the transmitting antenna to the receiving antenna along a waveguide path. The waveguide member is separated from the fluid flow path by an electrically insulating inner region of the wall. The waveguide member defines an opening disposed towards the fluid flow path to permit a portion of the electromagnetic field to extend through the opening and the inner region of the wall into the fluid flow path.

Abstract: A method for use in measuring a composition of a multiphase fluid which includes flowing a multiphase fluid through a fluid flow path defined by a wall of a fluid conduit is disclosed. The wall includes an electrically non-conductive material. The method includes establishing an electromagnetic field which extends through the electrically non-conductive material of the wall of the fluid conduit into the fluid and measuring a property of the electromagnetic field over a measurement time period. The method also includes transmitting additional energy through the fluid over the measurement time period independently of the electromagnetic field and measuring the additional energy transmitted through the fluid over the measurement time period. The method may be used to unambiguously determine a composition of a multiphase fluid which has different components.

Abstract: An apparatus for measuring a composition of a fluid has a fluid conduit with a wall defining a fluid flow path, a transmitting antenna, a receiving antenna, and an electrically conductive waveguide member for electromagnetic coupling with the transmitting antenna and the receiving antenna and for guiding an electromagnetic field from the transmitting antenna to the receiving antenna along a waveguide path. The waveguide member is separated from the fluid flow path by an electrically insulating inner region of the wall. The waveguide member defines an opening disposed towards the fluid flow path to permit a portion of the electromagnetic field to extend through the opening and the inner region of the wall into the fluid flow path.