Patent ID: 8826716

Claim:
A calibrator for an electromagnetic flow rate measurement system including a plurality of electromagnetic flowmeters arranged at intervals from one another in a peripheral direction of an annular flow passage in which an electric conductive fluid flows, the calibrator comprising: a flow passage for calibration corresponding to a part of the annular flow passage obtained by segmenting the annular flow passage in the peripheral direction; and an electromagnetic flowmeter for calibration provided in the flow passage for calibration, the electromagnetic flowmeter having: an excitation member for calibration that has a plurality of magnets for calibration arranged at intervals from one another along an outer peripheral surface of the annular flow passage in which the electric conductive fluid flows so as to form a magnetic field in a direction perpendicular to the outer peripheral surface of the annular flow passage; and a plurality of electrodes for calibration that are provided between the magnets of the excitation member so as to measure voltage generated when the electric conductive fluid crosses the magnetic field, wherein the calibrator is configured to calculate a relationship between voltage measured by the electromagnetic flowmeter for calibration and an amount of fluid flowing in the flow passage for calibration.