| 摘要 |
PROBLEM TO BE SOLVED: To detect differential noise as a large value and enhance the reliability of abnormality determination.SOLUTION: An electromagnetic flowmeter takes as a first period T1 a non-excitation period. until an end of a predetermined period from a start of transition from a positive excitation period to the non-excitation period, and as a second period T2 the non-excitation period until the end of the predetermined period from the start of transition from a negative excitation period to the non-excitation period, respectively; calculates the sum of a voltage to be produced at a detection electrode 4a and a voltage to be produced at a detection electrode 4b during the first period T1 and second period T2, respectively, as the sum of voltages between the electrodes; and determines an abnormality of the electromagnetic flowmeter (a detection of an empty state, adhesion of an insulating foreign substance to the electrode, and so on), based on the sum of voltages between the electrodes. |
