| 摘要 |
PURPOSE:To obtain an oxygen concn. meter having a long service life by using a metal (oxide) capable of reducing oxygen highly actively as a positive pole and lead as a negative pole, and using a mixed aqueous solution of an acetic acid, lead compound and alkali metallic salt or NH4 salt of a specified organic acid as an electrolyte. CONSTITUTION:In the galvanic cell type oxygen concn. meter, the metal such as Pt plate capable of reducing oxygen highly actively or the metal oxide is used as the positive pole 1, the lead as the negative pole 2, and a diaphragm 4 consisting of a copolymer such as F2C=CF2 and H2C=CH2 is fixed to a holder 6 made of PVC, etc. by an O-ring 5. The electrolyte of the concn. meter is the mixed aqueous solution of the acetic acid, PbO, the alkali metallic salt or the NH4 salt of the organic acid such as formic acid, acetic acid, propionic acid, butyric acid, maleic acid and glutamic acid, etc. In such a way, H2 generation is prevented, the precipitation of lead carbonate, etc. is not caused by CO2 in an outer atmosphere, the solubility of PbO is large. Thus the titled meter which is safer than conventional meter and has a long service life is obtained. |
