A Planar Conductometric Sensor Showing Excellent Polarization Impedance Characteristics

The measurement of conductivity of electrolytic solutions with relatively high ionic strength (physiological range), using micro-electrode structures, requires the elimination of the polarization impedance. Merely operating with ac-signals of some fixed frequency is inadequate, and may lead to erroneous data. An appropriate surface conditioning procedure is shown to improve the polarization characteristics of planar micro-electrodes in a substantial way, thus opening the way to accurate micro-conductivity sensors.