초록 ▼

An electromagnetic flow meter and method of operating the same. There is provided a flow measurement duct, a magnetic circuit including pole pieces for generating a magnetic field in fluid flowing in a direction in the duct across the direction of flow, and an electrical circuit including at least o

An electromagnetic flow meter and method of operating the same. There is provided a flow measurement duct, a magnetic circuit including pole pieces for generating a magnetic field in fluid flowing in a direction in the duct across the direction of flow, and an electrical circuit including at least one sensing electrode for measuring a voltage thereby induced in the fluid to provide an output indicative of the flow. The method comprises measuring a series of pairs of outputs of the electrical circuit, each pair of outputs comprising an output when the magnetic field is present and an output when the magnetic field is absent, and determining from the measured series of pairs of outputs whether fluid is present or absent in the duct.

대표청구항 ▼

[ What is claimed is:] [2.]2. An electromagnetic flow meter comprising a flow measurement duct, a magnetic circuit including pole pieces on opposite sides of the flow measurement duct, a structure operatively connected to the pole pieces and providing a path for magnetic flux, and a coil disposed on

[ What is claimed is:] [2.]2. An electromagnetic flow meter comprising a flow measurement duct, a magnetic circuit including pole pieces on opposite sides of the flow measurement duct, a structure operatively connected to the pole pieces and providing a path for magnetic flux, and a coil disposed on one of the pole pieces for generating a magnetic field across fluid flowing in the duct, an electrical circuit including a coil drive circuit branch connected to the coil, a pair of sensing electrodes in spaced relation and in fluid communication with the duct and a signal processing circuit branch connected to the electrodes for measuring a voltage induced in the fluid, for deriving a flow measurement therefrom, and for sensing presence or absence of fluid in the duct from a series of pairs of outputs of the electrical circuit, each pair of outputs comprising an output of the electrical circuit when the magnetic circuit is active and an output of the electrical circuit when the magnetic circuit is inactive.