Electrical Conductivity Sensing Circuit Design Using Voltage Divider

Abstract

Electroconductivity (EC) measurement is very integral in understanding soil condition in use as EC sensors in various industries. The main concern of EC measurement in a medium such as a liquid is the mitigation of electrode damage due to the presence of ions or electrolytes depositing on the surface of the electrode. This causes EC circuits to be very complex with many sensors in the market employing the use of sample and hold circuits. To address that, this paper proposes a circuit that has the same electrode damage mitigation capability but with lesser complexity using a simple voltage divider sourced by a single supply oscillating signal. This study then outlines how to use this new method with theoretical analyses on the output voltage to derive the conductivity of the solution. Experimental tests were conducted to determine how close the measured conductivity using the proposed circuit when compared with actual conductivity of the solutions.