| 摘要 |
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. <IMAGE> |
