2007 Volume 127 Issue 7 Pages 990-994
The aim of this study is to make clear the effect of temperature on the potentials of silver-silver chloride(Ag-AgCl) electrodes in potassium chloride(KCl) and sodium chloride(NaCl) solutions for micro biosensor applications. Non-isothermal coefficients, or thermal coefficient of Ag-AgCl electrodes in the concentrations of 0.1 to 1.0[mol/kg] were experimentally measured in the range of 15 to 45[°C]. The electrode was prepared by electrolytical process in KCl or NaCl solutions. The length and diameter of the electrode are 20[mm] and 3[mm], respectively. The coefficients in KCl solutions were 0.42[mV/°C] in 0.1[mol/kg] and 0.26[mV/°C] in 1.0[mol/kg] and almost the same in NaCl solutions. Isothermal coefficients were also measured. Although the coefficients must theoretically be zero by definition for all temperatures, the difference of potentials between a pair of electrodes which is called as offset voltage appears practically. They were 3∼4[μV/°C] in 0.1[mol/kg] and 0.3[μV/°C] in 1[mol/kg] at the steady state of temperature. The values were depending on the degree of the uniformity of electrode surface.
The transactions of the Institute of Electrical Engineers of Japan.C
The Journal of the Institute of Electrical Engineers of Japan