POTENTIOMETRIC DETECTION OF OXYGEN BASED ON THE MIXED POTENTIAL OF ZINC

A new potentiometric oxygen sensor is proposed, based on the mixed pot ential of zinc in a chloride electrolyte. Variations in the scn,or pot ential with oxygen concentration are the direct result of changes in t he corrosion rate of the zinc electrode due to diffusion-limited reduc tion of oxygen at it, surface. For static concentration measurements, the performance of the new (potentiometric) sensor is essentially equi valent to that of a traditional (amperometric) Clark sensor. For trans ient measurements, however. the response of the potentiometric sensor can be considerably faster than the analogous amperometric sensor, due to the sensitivity of the potentiometric method to logarithmic (rathe r than linear) variations in oxygen concentration.