Abstract: A digital flowmeter can include a vibratable conduit with a mixture of a liquid and a gas flowing therethrough. A driver can be connected to the conduit and can be operable to impart motion to the conduit where a sensor can also be connected and can be operable to sense the motion of the conduit. A digital transmitter can also be connected to the conduit and can include a void fraction determination system configured to determine a gas void fraction of the mixture, a viscosity determination system configured to determine a viscosity of the liquid in the mixture, and a flow parameter correction system operable to determine a flow parameter associated with the flowing mixture, based on the gas void fraction and the viscosity.

Abstract: A digital flowmeter can include a vibratable conduit with a mixture of a liquid and a gas flowing therethrough. A driver can be connected to the conduit and can be operable to impart motion to the conduit where a sensor can also be connected and can be operable to sense the motion of the conduit. A digital transmitter can also be connected to the conduit and can include a void fraction determination system configured to determine a gas void fraction of the mixture, a viscosity determination system configured to determine a viscosity of the liquid in the mixture, and a flow parameter correction system operable to determine a flow parameter associated with the flowing mixture, based on the gas void fraction and the viscosity.

Abstract: An electromagnetic flowmeter with conventional orthogonal electrode and magnetic axes (x, y) intersecting the flowtube axis (z) has its electrodes constituted by two pairs (1, 2 and 3, 4) of electrodes mounted in insulating tubing (5) on each side of the flow passage through the tubing. Four conductors extend respectively from the four electrodes to enable the potential difference between the two electrodes on each side due to an axial component on each side of eddy current electric field in the liquid to be determined for self-calibration purposes in compensating automatically for any extraneous change in the magnetic field and the average potential of each pair of electrodes can also be determined to derive the velocity of flow of the liquid. One of the two pairs of electrodes can be replaced by a single electrode.

Abstract: An electromagnetic flowmeter with conventional orthogonal electrode and magnetic axes (x, y) intersecting the flowtube axis (z) has its electrodes constituted by two pairs (1, 2 and 3, 4) of electrodes mounted in insulating tubing (5) on each side of the flow passage through the tubing. Four conductors extend respectively from the four electrodes to enable the potential difference between the two electrodes on each side due to an axial component on each side of eddy current electric field in the liquid to be determined for self-calibration purposes in compensating automatically for any extraneous change in the magnetic field and the average potential of each pair of electrodes can also be determined to derive the velocity of flow of the liquid. One of the two pairs of electrodes can be replaced by a single electrode.

Abstract: A magnetic flowmeter of the capacitively-coupled type includes low-input impedance detection circuitry which responds to a flow induced current signal that is related to the voltage induced at the electrodes by the intersection of the flowing fluid and a time varying magnetic field. An on-line measure of the electrode capacitance that is non-interactive with the flow induced current signal is accomplished by creating a voltage difference between the process fluid and the electrodes which causes a capacitance-related current to flow from the electrodes proportional to the value of the electrode capacitance as well as the rate of change of the magnetic field. In one embodiment the primary element and the detection circuitry are referenced to a different potential than that of the process fluid and the adjacent piping of the flow system.

Abstract: An electromagnetic flowmeter for measuring the mean velocity of a fluid flowing through a duct is described. In one embodiment the electrodes are shaped to provide a uniform weighting function relating fluid velocity distribution over the duct cross section to flowmeter output voltage representative of mean velocity. Flowmeters are described in which using large insulated electrodes sensitivity is made independent of velocity profile by either ensuring that the applied magnetic field is uniform and the virtual current in the duct is two dimensional, or vice versa.

Abstract: The flow velocity or flow rate of a fluid containing electrical charges or magnetic dipoles is sensed by receiving a noise signal generated by movement of the charges or dipoles, and determining the mean frequency of the received signal.

Abstract: An electromagnetic flowmeter comprises an iron tube surrounding a non-magnetic electrically insulating tube through which the fluid flows. Windings formed by printed circuit conductors are located on the inner surface of the iron tube and produce a main magnetic field in one direction in the electrode plane and subsidiary magnetic fields in the opposite direction upstream and downstream of the electrode plane.