Measurement of very low concentration of electrolytic solution by a novel contactless eddy-current sensor

Abstract

This paper presents an eddy-current sensor with a novel contactless structure to determine the very low concentration of electrolytic solution. By detecting the change in inductance of the sensing coil due to formation of eddy-current inside the conducting solution it is possible to determine the very low concentration of electrolyte solution. Concentration as low as 1 ppm for strong electrolyte is possible to measure. It was tested for various concentrations of NaCl. It shows distinct response for each concentration.