| 摘要 |
An apparatus for electrochemical indication of the final stage of a titration analysis has a first indication electrode located in an electrochemical titration container connected by a switch to a sampling current amplifier feeding a recorder. Both the amplifier and the switch are controlled by a timing circuit which causes the switch to connect and disconnect the electrode to the amplifier. By only connecting the electrode to the amplifier for a brief time and activating the amplifier for a brief time thereafter, the instantaneous value of indication current is obtained. During the remaining time period, the indication electrode is galvanically disconnected from the amplifier and consequently, no reduction of concentration of electroactive substance in the proximity of the electrode occurs and an extremely high current response is attained. In operation of the apparatus, there is also effectively suppressed the undesirable charging current since the indication electrode, once disconnected, does not lose but a neligible portion of electric charge. The high sensitivity of the apparatus is achieved, according to the invention, in connection with both the single and two indication electrodes. |
