Optimization of Coil Width and Magnetic Field Switching Speed for Non-Contacted Electromagnetic Flowmeter

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.