Electromagnetic flowmeter (EMF) is a widely used flow measurement instrument in the 20th century. It is based on the Faraday’s law and developed rapidly in recent decades. It plays an important role in our daily life such as water treatment, food production and chemical industry. An improved excitation structure with E-type frame made by permeable material added in the traditional Helmholtz coil is proposed in this paper to simulate the distribution of the magnetic field. The optimal coil width is obtained which can ensure the uniformity of magnetic field with minimum physical size. A compensate method is discussed to improve the switch speed of the magnetic field so that the EMF can be used to measure fast flow.

中文翻译：

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非接触式电磁流量计线圈宽度和磁场切换速度的优化

电磁流量计（EMF）是20世纪广泛使用的流量测量仪表。它以法拉第定律为基础，近几十年来发展迅速。它在我们的日常生活中扮演着重要的角色，例如水处理、食品生产和化学工业。本文提出了一种在传统亥姆霍兹线圈中加入导磁材料制成的E型框架的改进励磁结构来模拟磁场的分布。得到最佳的线圈宽度，以最小的物理尺寸保证磁场的均匀性。讨论了一种补偿方法来提高磁场的切换速度，从而可以使用 EMF 来测量快速流动。