Experimental method of mis measurement of an electrolytic cell with a passive wireless sensor

This paper presents a three coil system, with a passive wireless sensor, as an interface for a commercial network. The objective of this experiment is to achieve the system measurement of the impedances of electrolytic solutions using the magnetic impedance spectroscopy method. The interface is based on planar coils over a laminated printed circuit board; one of the planar coil acts as transmission antenna, another one is inside the electrolytic cell and the last acts as a receiver antenna. The receiver is positioned and oriented of such form that its plane is perpendicular to the plane of the transmitting antenna in order to minimize the induced voltage due to the transmission antenna. The inductive-capacitive passive remote sensor circuit consists of a square planar coil in parallel with an inter-digital electrode with a capacitance of 18 pF. It is oriented with an angle of 45deg respect to the plane of the transmitting coil. The performance measurements show a good correlation between the measured and calculated induced voltages on the receiver. We measured three different electrolytic solutions inside the cell with different ion concentrations.