| 摘要 |
PURPOSE:To avoid effect of dissolved oxygen by covering one surface of a conductive substance with a porous film of hydrophobic nature and other surface with a hydrogen-ion penetrating film and contacting hydrogen or oxygen gas with the surface on the porous film side. CONSTITUTION:An ion sensor 10 is of a construction that, a porous film 12 of hydrophobic nature allowing hydrogen and oxygen gases to penetrate is formed over one surface of an conductive substance 11, such as of a metal, and an ion-penetrating film 13 permeable to hydrogen and oxygen ions in a solution is formed on the other surface. This sensor is arranged in a cell 20 consisting of liquid chamber 21 and gas chamber 22 and in the liquid chamber 21 a solution 23 for measuring hydrogen ion concentration is contained and into the gas chamber 22 hydrogen or oxygen gas is introduced and by measuring an emf. between the standard electrode 24 and conductive substance 11 is measured to determine a hydrogen concentration. Upon introducing hydrogen gas into the chamber 22, an equilibrium value (equilibrium electric potential value) is stabilized and upon introducing oxygen gas, effect of dissolved oxygen in the solution 23 is avoided allowing measurement of hydrogen ion concentration. |
