| 摘要 |
<p>Method and apparatus are disclosed for the electrochemical determination of an electrochemical reactive substance in a fluid stream and for simultaneously determining and subtracting from the current flow due to the reaction of the sought for substance, current flow caused by non-Faradaic conditions and other non sought for electrochemically reactive substances. The sensor consists of a counter electrode (40), a sensing electrode (32) and a compensating electrode (36). The sensing electrode is biased to the concentration polarization potential of the sought after substance while the compensating electrode is biased to a different potential sufficiently low to cause current flow between the counter electrode and the compensating electrode due to non-Faradaic phenomena and/or other electrochemically reactive substances which react below the potential of the sensing electrode. Circuitry is provided for subtracting the compensating electrode signal output from the sensing electrode signal output and the difference is a signal which represents the diffusion current flow due to the electrochemical reaction of the sought after substance.</p> |
