Abstract
The large size electromagnetic flowmeter was tested to investigate the variation of its error characteristics in the range of low velocity under 0.6 m/s using flowmeter calibration system. For the two case of valve opening rate 100 % and 50 %, these tests were undertaken three times each for twelve velocity condition from $0.05\;^m/s\;to\;0.6\;^m/s$ with increment of $0.05\;^m/s$. It is shown that error characteristic of electromagnetic flowmeter was stabilized within ${\pm}0.4%$ of rate both higher than $0.25^m/s$ of velocity condition and 50 % of valve opening position. But, measurement deviation of flowmeter for ${\Phi}400mm\;and\;{\Phi}600mm$ was out of expected deviation range. It is necessary to correction with calibration. In conclusion, error characteristic of electromagnetic flowmeter wasn't changed proportion to its size.
