| 摘要 |
1,131,325. Electro-chemical analysis. SVENSKA ACKUMULATOR A. B. JUNGNER. Nov. 2,1965 May 5, 1965 ] , No.46400/65. Heading G1N. In order to effect coulometric titration of a flowing medium the medium is vigorously agitated and caused to flow in an approximately helical path along the curved wall of a chamber first past the anode, then past an indicator electrode and a reference electrode, then through an outlet at the far end of the chamber and finally into contact with the cathode. In one embodiment liquid entering at 20 is forced by a rotating impeller 28 and helical baffle 26 to flow along the cylindrical wall of the chamber 18 towards the anode 36, and a combined indicator and reference electrode 41 before passing through a plug of glass wool 24 (or sintered glass discs, Fig. 3 (not shown) or ion-exchange diaphragms with by-pass passages, Fig. 4 (not shown) to the cathode 38 and outlet 22c. The volume of the chamber 18 is about 30 times larger than the volume of liquid passing through it per minute. In a modification, Fig. 6 (not shown) the cross-section of the chamber 18 is elliptical. In another modification, Fig. 7 (not shown), for analyzing sulphur dioxide in the form of a suspension of small bubbles in sodium sulphate solution, the chamber is separated from the cathode by a pair of ion-exchange diaphragms extending in parallel right across the cell. The anode and cathode may be made of platinum, gold, or silver, or the anode may be a platinum coil in a jet of sodium sulphate. The indicator - electrode may be of glass or of silver and the reference electrode may be of silver/silver chloride, or calomel, or of mercury sulphate and platinum. The power supply to the cell is automatically controlled as in Specification 1,131, 324 in which the working current is proportional to the difference between measured pH value and the butput of the reference electrode, hence, provided the flow rate is not too high the current varies in the proportion to the momentary concentration of reducible and oxidizable components in flowing medium. |
