DRY CALIBRATION TECHNIQUE OF

ELECTROMAGNETIC FLOWMETERS

FU Xin  HU Liang  XIE Haibo Y ANG Huayong

(State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027 )

Abstract: Dry calibration technique of electromagnetic flowmeters is presented, including its principle, present research status and prospect of industrial application. The precise measurement of the distribution of magnetic field in the effective zone of the electromagnetic flowmeters is indicated as the key factor which impacts the industrial application of dry calibration technique. The direct measurement of the distribution of magnetic field, however, is presently unavailable, therefore, an effective method is introduced to obtain indirectly the distribution of magnetic field through measuring other physical parameters caused by the electromagnetic induction using the alternating characteristic of magnetic field. The principle, features and implement of two indirect dry calibration methods, eddy current field measurement method and surface weighting function method, are discussed, which provides a useful reference for the research of dry calibration technique of electro-magnetic flowmeters and its industrial application in China.

Key words: Electromagnetic flowmeter Dry calibration Eddy current field Weighting function

CLC No: TH814.93

国家科技攻关计划(2005DFBA0008)和国家重点基础研究发展计划(973计划, received in revised form 2006CB705400)资助项目. Received 20060604, received in revised form 20061222