Measurement of concentration of electrolytic solution based on novel non-contact multi-sensing technique

It is important to analyze the ingredient of electrolytic solutions for industrial use to prevent the environmental pollution. In this paper, a new approach for the measurement of low concentration of electrolytic solutions using multi-sensing technique is presented. For achieving this multi-functional sensing function, a novel structure is proposed for the multi-functional sensor. Two sensing functions namely the inductive and the capacitive sensing functions can be realized by this sensor. From these sensings, two databases are prepared and then the unknown concentration is precisely determined by comparing with these databases. Experimental results using the sensor on various solution of low concentration of NaCl, K/sub 2/SO/sub 4/ and Pb(NO/sub 3/)/sub 2/ electrolytes show distinct response to various concentrations as well as to different solutions. The concentration as low as 1 ppm of solution is possible to measure by this sensor.