| 摘要 |
PURPOSE:To exactly measure an object material by biasing a current/voltage converter at the time of applying a forward bias to an electrode and reverse bias thereto by the current/voltage converter. CONSTITUTION:The electrode 4 is forward biased when a cathode side electrode 4b is grounded by outputting a voltage 0V from a reverse bias supplying terminal 5 in the case of measuring the object material. The current corresponding to the quantity of the material formed or annihilated by the reaction of the fixed enzyme of an immobilized enzyme film and the object to be measured, therefore, flows in this state from the anode side electrode to the electrode 4b. Since a diode 3 is held non-conducting at this time, the voltage signal superposed with an offset voltage by the forward bias on the voltage signal proportional to the current is taken out of the output terminal 1c of an operational amplifier 1 for current/voltage conversion. Refreshment of the electrode is executed simply by outputting the voltage higher than the partially divided voltage conversely from the terminal 5. The exact measurement is thus permitted. |
