Signal modeling of electromagnetic flowmeter under sine wave excitation using two-stage fitting method

The current signal models of electromagnetic flowmeter under sinusoidal excitation cannot describe quantitatively the relationship among the sensor output, flow rate and exciting signal. A two-stage fitting method is proposed to build up the accurate signal model based on experimental data. The first step of the method is to approximate the relationship between the sensor output and the flow rate, and the second one is to fit the relationship between the model coefficients and the frequency or amplitude of exciting current. This method can determine the terms and coefficients of signal model, and reflect the effects of transformer and eddy current.