Abstract
The advantages of Krogh's apparatus are, first, the small amount of fluid required; second, the large specific surface obtained; third, the rapidity and accuracy of determinations. The bubble of gas used is about 2 mm. in diameter, having a specific surface of 30 as compared with a specific surface of 3.3 in Pflüger's aërotonometer, 5.2 in Bohr's hemataërometer and 3.7 in Fredericq's. A fine spray of the fluid to be examined is played on the bubble for a few minutes; the bubble is then drawn into a capillary burette where it is measured before and after the absorption of oxygen and carbon dioxide. For carbon dioxide alone in fluids, a very simple vessel is used; the tonometry is accomplished by shaking a small bubble of air with a relatively large amount of fluid. The bubble is then transferred to the capillary burette and analyzed. The limit of error can be brought down to + 0.2 per cent. 1
Get full access to this article
View all access options for this article.