摘要 |
The hydrogen ion concentration or pH of liquids may be measured, particularly in industrial or municipal processes, by a combination glass electrode system containing a glass electrode, a reference electrode and a liquid junction connecting the reference electrode with the process liquid. Both the measuring glass electrode and the reference electrode are the same kind of all-solid-state glass button electrodes, electrically connected to an impedance-transforming integrated circuit; all these components being encapsulated in a hermetically sealed shell. The reference electrode is in mechanical contact with a reference gel, external to the sealed enclosure but isolated from the process liquid and in ionic contact with this liquid only at the liquid junction.
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