Summary: | 碩士 === 國立交通大學 === 電子物理學系 === 85 === A microreference electrode based on sputtered IrO2 and an
internal electrolyte derived from PVA / H3PO4 / KH2PO4 has
been tested. The solid electrolyte consists of a buffer. An
epoxy shield separaties the electrolyte from the external
environment. Only a narrow salt bridge connects with the
external electrolyte. Since the concentration of H+ in the
internal electrolyte remains unchanged, according to the Nernst
equation, the IrO2 potential should also be constant when
shielded from external redox i The open-circuit of this IrO2
microreference electrode was found to have a temperature
coefficient of 2.17 mV/℃. Under temperature control, it was
found to be stable and reproduceable both in N2 and air purged
KCl solutions. The potential drift is on the order of 35 mV/hr.
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