| 摘要 |
The method passes air flows (arrow) through two glass tubes (2,5), each with length (L) of 10 cm. and internal diameter (D) about 0.7 cm. They are joined by a plastic coupling (8) with internal supporting shoulders (11,11'). A stainless steel partition (7) has a small opening (9). A paper strip (10) impregnated with reagent is placed in one tube (2). The reagent e.g. phosphoric acid in ethanol, is applied in a nitrogen atmosphere and kept in a sealed container until needed. Accuracy of measurement is enhanced if the distance between inlet and outlet is reduced e.g. by folding the tubes into a modified U-shape. |
