| 摘要 |
PURPOSE:To provide the titled instrument which has a smaller long-period drift and has a wide range of measurable concn. by short circuiting an electrode prior to measurement or impressing the voltage reverse from the direction of the voltage in the measurement stage thereto. CONSTITUTION:A means 8 for controlling the impressed voltage consists of a voltage impressing means 9 which impresses the voltage in the specified direction to both terminals of the hydrogen peroxide electrode in the stage of measuring the concn. and an impressed voltage regulating means 10 which short circuits both terminals of the hydrogen peroxide electrode by a switch, etc., or impresses the voltage in the direction reverse from the direction of the voltage in the measurement stage to both electrodes of the hydrogen peroxide electrode by receiving an input signal from an external signal input means 11. The platinum oxide film formed on the surface of a platinum electrode is thereby removed and the surface of the platinum electrode is activated, by which the long-period drift is prevented and the output current from the electrode is increased. The hydrogen peroxide electrode to be used is a commonly used hydrogen peroxide electrode which is exemplified by an electrode using platinum for the anode and silver for the cathode, etc. |
