A study on error characteristics of large size electromagnetic flowmeter in the range of low velocity

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 ±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 φ400 mm and φ600 mm 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