Study on Slurry Noise of Electromagnetic Flowmeter Based on ARMA Power Spectrum Estimation

The output signal of the electromagnetic flowmeter measuring the slurry flow will be disturbed by the slurry noise. It is necessary to study the characteristics of slurry noise in order to reduce the interference. The methodology for the estimation of the slurry noise power spectrum based on the ARMA model is presented in this paper, and the relation among the slurry noise, the velocity, and the concentration is obtained by means of the methodology above according to the 1/f characteristics of the slurry noise. The results by computer simulation experiment show that if the concentration or flow velocity is increased, then slurry noise power spectral density curve in the logarithmic coordinate system will move to the upper right; if the concentration or flow velocity is reduced, then slurry noise power spectral density curve in the logarithmic coordinate system will move to the lower left.