Harmonic Distortion In The Flow Signals Of Externally Mounted Capacitive Spatial Filter

Abstract

This paper investigates the performance of some windows on the flow signals that are generated from the planar capacitance spatial filter (PCSF) according to the moving of the solid particle in the channel of the filter. The finite-difference equations are solved using successive over relaxation (SOR) methods, The waveforms show that the response of the PCSF is spatially-biased towards particle flowing closer to the plane of sensing electrodes and that the resulting flow signal is non-sinusoidal. The total harmonic distortion (THD) content on the flow signals are calculated with respect to the fundamental frequency of the power spectrum density through a specific quantitative criterion. This paper comprises a comparative study among three types of windows; Hanning, Hamming, and a suboptimal window called the Kaiser window. The effect of particle flying heights and relative permittivity on the THD of the flow signal was examined.