Abstract
Electromagnetic flowmeters are used widely in the sodium test loops and fast breeder reactor plants, and recognized to be one of the most reliable ones. But it is possible that the electromotive force of the flowmeters decreases by the decrease of magnetic flux density and by the increase of sodium inpurity. From these reasons, there is the cross correlation with flow fluctuation signals as one of the in-situ calibration methods.
For the establishment of this method, sodium flow measurement tests were conducted using the 6 inches electromagnetic flowmeter. And for the flow range of 1∼5m/s, calibration was confirmed to be possible within the accuracy of ±4%. These results were found to be realized under the following conditions; (1) Electrode are settled at the direction of 45° from the center of the pipe, (2) Flow fluctuation frequency of 15∼20Hz are used by the band pass filter, (3) Distance between electrods is 150mm, (4) Correction coefficient to the flowmeter output is 1.00.
In future, effectiveness of this method would be confirmed for larger flow pipe.
