Correction factors of IDEs for precise conductivity measurements

Thick-film Pt interdigitated electrodes (IDEs) are used as miniature and cheap chemical sensor for widespread use as conductivity-based transducer. The planar sensor has been characterised by a precise impedance analyser over a wide range of frequencies and conductivities. The frequency characteristics have been studied to describe the electrode behaviour, and for comparison with theory. We found relations between conductivity and frequency. The ridge frequency was detected as suitable measuring frequency to improve accuracy. Extracted relations can be used as correction characteristics. The correction factor was determined for wide range of conductivity to take precise measurements without cell replacement.