| 摘要 |
1,086,096. Determining nitrite / hydroxide ratio by titration. STAMICARBON N.V. Dec. 1, 1964 [Dec. 2, 1963], No. 48815/64. Heading B1X. [Also in Division G1] In apparatus for automatically determining and/or controlling the hydroxide/nitrite ratio of a nitrite solution a metered sample of the nitrite solution is admitted to a first titration vessel 5 where it is titrated with amidosulphuric acid solution from a burette 2 until the equivalence point, pH-5, as determined by a glasscalomel electrode system 8, is reached. The solution is then automatically transferred to a second titration vessel 11 surrounded by a heating jacket 12 where it is heated to between 30‹C and 80‹C and 0.5N sulphuric acid is added to lower the pH to between 2.0 and 3.5. After a delay of at least half a minute the solution in vessel 11 is titrated with a standard solution of amidosulphuric acid or of nitrite from a burette 3 or 4 respectively as necessary depending on a companion between the voltage drop across two platinum electrodes 16 and a reference voltage in a trigger circuit 19. The volumes consumed from the burettes are passed to a computer 9 which calculates the hydroxide/nitrite ratio which may be stored in memory 21. The apparatus may be used to prepare a solution having a hydroxide/nitrite ratio of unity for use in preparing hydroxylamine. |
