| 摘要 |
PROBLEM TO BE SOLVED: To correct a span error caused by insulation deterioration between a magnetic field generation means and a measuring tube, relative to a flow rate signal. SOLUTION: An ammeter 100 includes a pair of measuring electrodes 4, 5 disposed in the facing state into fluid flowing in a pipe 1, an earth electrode 6 disposed in the facing state into the fluid, a coil 3 for generating a magnetic field to the fluid, an excitation circuit 30 for outputting an excitation current into the coil, a flow rate signal detection means for detecting the flow rate signal of the fluid based on a signal output from the measuring electrodes 4, 5, a leakage current detection means for detecting a leakage current from the coil 3 into the pipe 1, and a CPU 26 for calculating the span error, based on the excitation current output from the excitation circuit 30 and the detected leakage current and correcting the detected flow rate signal, based on the span error. COPYRIGHT: (C)2008,JPO&INPIT
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