| 摘要 |
PURPOSE:To stabilize measurement by dividing medium liquid by a gas permeable intermediate membrane. CONSTITUTION:Further another gas permeable intermediate membrane 4 is provided between a measuring electrodes 3 and a gas permeable diaphragm 1, so that medium liquid is divided substantially to two systems, a system 5 on electrode side and a system 6 on diaphragm side. Then, in the system 5 on electrode side, pH or ORP changes with the gas infiltered past the diaphragm 1 and the intermediate membrane 4 and the gas concentration balances with that in the measuring target of the outside, and in the system 6 on diaphragm side, moisture evaporates and dissipates through the diaphragm 1 but the dissipation of the moisture does not affect the system 6 on electrode side. Hence, even if the gas to be examined is dry, the occurrence of the change in concn. is prevented by the evaporation of the medium liquid near the measuring electrode 3 and the stable measurment is made possible. |
