전자기유량계의 개발및 신호 특성에 관한 연구

A study on the development of an electromagnetic flowmeter and the characterization of flow signal

An electromagnetic flowmeter(EMF) was developed and its characteristics were compared with a commercial EMF. The measuring tube of the EMF was basically designed as 100 m diameter. A signal processing circuit was also developed for generating the magnetic field and converting the flow signal to flowrate and flow quantity. To obtain a more stable and reliable flow signal, the double magnetizing frequency was adopted for magnetizing the coil of the EMF For the characterization of EU, the uncertainty of calibrator was estimated within ${\pm}0.5{\%}$, the method of estimation was in accordance with the ISO 17025 recommendation. It was found that the flow signals between the electrodes were about ${\pm}60\;-\;{\pm}300{\mu}V$, which were sufficient for the discrimination of the flowmeter and protecting the noise. The test result against the calibrator, showed the good linearity in the range of $3 m^{3}/h\;and\;70m^{3}/h$. A commercialized design of the EMF will be technically more competitive in domestic and foreign market.