| 摘要 |
An improved reference electrode is disclosed for use in potentiometric measurements of the amount of ions in an aqueous solution. The reference electrode illustratively comprises a metal member on a substrate, and a layer of a salt reversible to the ion X overlying the metal member. The reference electrode is overlaid by a quantity of an electrolyte, which may be a polymer gel having a salt including the ion X dispersed therein. This structure is overlaid by a membrane permeable to water but not to the ion X that extends beyond the portion of the electrolyte overlying the electrode, but leaves a portion of the electrolyte exposed. This assembly may be shipped dry. In use, when the electrode is disposed in an aqueous solution containing an ionic species to be measured, water permeates the membrane and "wets up" the electrolyte relatively quickly. Any changes in ionic concentration, however, have to be made over a substantially longer path through the electrolyte between the electrode and the exposed portion such that the transit time for such changes is substantially longer than the wet-up time of the electrolyte. This reference electrode may be used in combination with a wide variety of potentiometric indicating electrodes or other structures.
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