| 摘要 |
PURPOSE:To calibrate an electromagnetic flow meter while it is fitted at an in-use place by providing a conversion part with an integrating function, turning on and off its integrating operation with an external switch, and making a flow to the measurement tube of a detection part by a constant accurate quantity which is a calibrated value in the on state. CONSTITUTION:Neither the integrating function 17 nor an arithmetic function 19 operates except when an injector 21 is put in operation at the time of calibration, so a conversion part 11 processes a signal amplified with a preset amplification factor into a signal proportional to a flow rate and outputs it to the outside. When the calibration is performed, the injector 21 makes a flow to the measurement tube 2 by a constant quantity to measure an integral flow rate from the on operation of the integrating function 17 to the off operation by switches 24 and 25 of the injector 21. When the integrating operation is off, the arithmetic function 19 compares the integral flow rate obtained by the integrating function with the constant injection quantity to decide whether or not the amplification factor of the conversion part 11 is large, and the amplification factor of the conversion part is adjusted so that the integral flow rate becomes equal to the constant quantity, thereby finishing the calibration.
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