A new method of capacitively coupled contactless conductivity detection based on series resonance

Based on the series resonance principle, a new method of capacitively coupled contactless conductivity detection ((CD)-D-4) is proposed to improve the detection resolution and to expand the detection range of the (CD)-D-4. With the introduction of an inductor module, at series resonance, the influence of the coupling capacitances formed by the metal electrodes, insulating pipe and electrolyte solution on conductivity detection is eliminated. Meanwhile, a new shield configuration is designed to remove the influence of the stray capacitances. The experiment results show that the proposed method is an effective detection method. Compared with the existing (CD)-D-4 methods, it has the advantages of high resolution and wide detection range. (C) 2009 Elsevier B.V. All rights reserved.