| 摘要 |
PURPOSE:To obtain a long-life polarograph type oxygen densitometer by using a highly active metal for electrolytically reducing O2 as cathode and Pb or Cd as anode while a mixed aqueous solution of organic acid and an alkali metal salt thereof is employed as electrolytic solution. CONSTITUTION:A highly active metal such as Pt for electrolytically reducing O2 is used as cathode 1 and Pb of Cd as anode 2. An aqueous solution of organic acids such as acetic acid, propionic acid and n butyric acid with a large dissolubility for water and an alkaline metal salt of these organic acids for a larger electric conductivity is provided as electrolytic solution 3. A membrane 4 comprising ethylene tetrafluoridebutylene hexafluoride copolymer or the like is fixed on a holder 6 made of polyvinylchloride or the like using an O ring 5 to form a polarograph type oxygen densitometer. As PbO and Cd<2+> generated by an anode reaction are dissolved by organic acid, the surface of the anode 2 is renewed ceaselessly to stabilize the potential. This also provides a long-life densitometer free from interference by CO2 gas as the electrolytic solution 3 is acid. |
