Yamatake-Honeywell Co., Ltd.

Atsushi Koshimizu

Ichiro Mitsutake

Hiroshi Okaniwa

In an electromagnetic flowmeter for obtaining a signal corresponding to flow rate of conductive fluid in a magnetic field, a noise detector detects a noise superimposed on the fluid, and a timing signal generator produces timing of generating an exciting current to produce the magnetic field and timing of sampling electrical potential generated in electrodes in the fluid, based on the noise detected by the noise detector.

Electromagnetic flowmeter

An electromagnetic flowmeter for obtaining a detection signal by sampling voltages generated from electrodes in contact with a conductive fluid flowing in a magnetic field at a predetermined timing includes an external noise detecting section, a pseudo-noise signal generating section, and a timing signal generating section. The external noise detecting section detects external noise, superposed on the fluid, from the electrodes. The pseudo-noise generating section supplies a pseudo-noise signal for a predetermined period of time if the external noise detecting section determines that no external noise signal is detected. The timing signal generating section generates a timing at which an excitation current for generating the magnetic field is generated, and the sampling timing on the basis of the pseudo-noise signal while the pseudo-noise signal is kept supplied, and causes the external noise detecting section to generate the timing at which the excitation current for generating the magnetic field is generated, and the sampling timing while no pseudo-noise signal is supplied.

An electromagnetic flowmeter includes a measuring pipe and a cylindrical case. The measuring pipe has a pair of pipe connecting flanges at both ends of its outer surface. The cylindrical case surrounds the outer surface of the measuring pipe so as to cover a pair of excitation coils arranged on the outer surface of the measuring pipe, and is welded and fixed to ring-like collar portions extending from inner surfaces of the flanges. The thickness of the ring-like collar portions to which the case is welded and fixed is set to be larger than that of the case.

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Tokyo, Japan

Atsushi Koshimizu