| 摘要 |
PROBLEM TO BE SOLVED: To provide an electromagnetic flowmeter which enhances its differentiation noise/fluid noise removal performance, is hard to allow saturation of a signal processing circuit occur, and moreover is capable of determining emptiness of a fluid to be measured in the course of flow rate measurement. SOLUTION: This flowmeter includes a differential amplifier 4 for amplifying a signal detected between electrodes to generate a detection signal, a clamp circuit section 5 for clamping the detection signal to a predetermined reference potential at timing of the respective center positions of positive and negative exciting signals, an operation part 6 for finding the difference between a first average value of square wave signals in a positive direction after being clamped, and a second average value of the square wave signals in the negative direction from output signals of the clamp circuit section, to find a flow rate from the found signal, and a control part 7 for generating control signals for controlling the exciting signals, clamp timing signals for the clamp circuit section, and an operation timing signal for finding the difference between the first average value and the second average value. COPYRIGHT: (C)2010,JPO&INPIT
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