| 摘要 |
The concentration of azide ions (N3<->) or hydrazoic acid (HN3) in a test solution, is determined by a pH electrode and a reference electrode both surrounded by a hollow body 5, the wall of which is partially formed by a semi-permeable diaphragm 2, which dips into the test solution 1, the interior of the hollow body 5 being filled with an inner filling solution 3, which is produced by dissolving 0.2 to 5 x 10<-3> mol of an easily soluble azide in one litre of water. The test solution has a maximum pH value of 2. Between 5 x 10<-3> and 1 mol per litre of a further salt may be added to the filling solution; the further salt being completely soluble in the solution and unreactive with azides or hydrazoic acid. Its purpose is to render the ionic strengths of the test and filling solution equal. A gas-sensitive sensor of the above construction is also claimed. <IMAGE> |
