A magnetic flowmeter has a conduit, an electrical coil, and a coil driver configured to energize the electrical coil with a periodic electrical signal and generate a magnetic field in the conduit that periodically reverses polarity. Electrodes are arranged to detect a voltage generated by flow of the conductive fluid through the conduit and through the magnetic field. A measurement system receives electrical signals from the electrodes and determines a flow rate of the conductive fluid using the electrical signals. The flowmeter has a meter verification system that includes a sensor configured to detect the magnetic field generated by electrical coil when it is energized by the coil driver. The meter verification system is configured to determine an amplitude of the periodically changing magnetic field and to use this amplitude to assess the current operational effectiveness of the magnetic flowmeter.

An electromagnetic flowmeter for monitoring a flow rate of a fluid includes a conduit and an electromagnetic assembly coupled to the conduit to generate a magnetic field inside the conduit. A ring assembly modifies a velocity profile of fluid arranged on an inner liner wall of the conduit. A position of the ring assembly is adjustable along the inner liner wall to varyingly reform the velocity profile of the fluid. A pair of electrodes mounted to the conduit detects induced voltage generated within the reformed fluid due to the magnetic field. The flow rate of the fluid is determined based on the induced voltage.

An electromagnetic flowmeter and method for measuring a flow of a fluid through a conduit includes utilizing at least two coils, at least two electrodes, and a control circuitry. The at least two coils are electrically excited to generate a magnetic field within a flowmeter fluid space. First and second coils are placed around first and second central axes of the conduit. The at least two electrodes are arranged diametrically opposite to each other to detect an induced voltage in the flowmeter fluid space in response to the generated magnetic field. The control circuitry for measuring the induced voltage on each of the at least two electrodes provides a measure of flow of the fluid.

According to one embodiment, an electromagnetic flowmeter includes a tube, a lining, at least one protrusion, and a pair of electrodes. A fluid to be measured flows in the tube. The lining covers an inner surface of the tube. The protrusion protrudes from the inner surface and includes a hook for hooking the lining.

A flowmeter includes an exciter configured to excite fluid which is a measurement target, a state detector configured to detect a state of the fluid excited by the exciter, a driver configured to supply exciting current for driving the exciter, a first current detector that is disposed between the exciter and the driver, the first current detector being configured to detect the exciting current, and a processor configured to diagnose insulation deterioration of the exciter in accordance with a change of a detection result of the first current detector.

An apparatus for measuring flow of a fluid flowing using the magneto-inductive measuring principle, comprising a measuring tube having at least two subsections, wherein the subsections differ in diameter and/or geometry of cross sectional area; at least one magnet system having at least two coils for producing a magnetic field directed essentially perpendicularly to the flow direction of the fluid; at least two measuring electrode pairs for sensing induced voltage, wherein at least one measuring electrode pair is arranged in a first subsection and a second measuring electrode pair in a second subsection, wherein each measuring electrode pair includes first and second measuring electrodes, which lie opposite one another in the measuring tube and the respective connecting lines of the measuring electrodes are perpendicular to the tube axis and perpendicular to the magnetic field, and an electronics unit for signal registration and/or evaluation and for power supply of the coils, wherein the electronics unit is so embodied that it determines from the induced voltage the flow velocity of the fluid and/or the flow rate of the fluid for at least one subsection.

According to one embodiment, an electromagnetic flowmeter includes a measurement pipe, a first coil, a second coil, core members, and an electrode. An object to be measured flows through the measurement pipe. The first coil is provided radially outside the measurement pipe, the first coil generates a magnetic field in the measurement pipe. The second coil is provided radially outside the measurement pipe and forms a pair with the first coil, the second coil generates the magnetic field in the measurement pipe. The core members are provided in an inner circumference of the first coil and an inner circumference of the second coil in a radial direction of the measurement pipe. The electrode is provided in the measurement pipe, the electrode detects induced electromotive force generated from a flow of the object to be measured through the measurement pipe. The inner circumference of the first coil, the inner circumference of the second coil, and an outer diameter of the core member have shapes such that the core members can be provided in the inner circumference of the first coil and the inner circumference of the second coil.

A flow monitoring system is described for monitoring flow of a mixed-phase sample comprising at least a first phase and a second phase having different electrical conductivities, the second phase being a liquid or a gas and substantially electrically non- conductive and the first phase being a liquid and having a conductivity higher than the second phase. The system comprises: a conduit through which the mixed-phase sample can be arranged to flow; tomography apparatus arranged to generate tomography data indicative of at least a first conductivity profile of at least a portion of a first cross section of the mixed phase sample when flowing through the conduit; a flow meter arranged to detect flow of the first phase though the conduit and provide a flow signal indicative of a flow velocity of the first phase; and processing means adapted to calculate, from said data, a fraction of said first cross section occupied by the first phase, and calculate, from said fraction and said flow signal, a volumetric flow rate of the first phase through the conduit.

A method for manufacturing an apparatus for measuring flow of a fluid flowing through a measuring tube of metal using the magneto-inductive principle, comprising the method steps as follows: securing first and second collars of metal externally on the measuring tube with an orientation perpendicular to the tube axis of the measuring tube lining the measuring tube internally with an electrically non-conductive, elastic liner and altering a measuring section of the measuring tube located at least partially between the first collar and the second collar by means of cold deformation in such a manner that the cross sectional area of the measuring section is reduced compared with the cross sectional area of an inflow section of the measuring tube located upstream from the measuring section and an outflow section of the measuring tube located downstream from the measuring section.

According to one embodiment, an electromagnetic flowmeter includes, for example, a pipe, a lining, and a first double-faced tape. A fluid to be measured flows through the pipe. The lining includes a first portion which covers at least the inner face of the pipe. The first double-faced tape is placed between the inner face and the first portion to bond the pipe and the lining.