| 摘要 |
PURPOSE:To obtain an ion electrode measuring device without any leak current to an indicated electrode body regardless of insulation resistance of a sealed portion. CONSTITUTION:An ion electrode measuring device is provided with an indicated electrode 1, a comparison electrode 2, and a first amplifier 3 of a high input impedance which outputs a voltage which is logarithmically proportional to a differential voltage between the indicated electrode and the comparison electrode. A second amplifier 4 with a single gain and a high input impedance is placed between an electrode body 7 of the indicated electrode and an internal pole 6 of the indicated electrode. Since a potential of the internal pole 6 equals that of the electrode body 7 due to operation of the second amplifier 4, no leak current flows from the internal pole 6 to the electrode body 7. |
