3061.     SCHENCK, R., DINGMANN, T.  [Equilibrium Studies in the Reduction, Oxidation, and Carburization Processes of Iron.  XII.]  Ztschr. anorg. Chem., vol. 209, 1932, pp. 1-10; Chem. Abs., vol. 27, 1933, p. 1302.

        Micro methods of gas analysis used in this series of investigations are described.  Apparatus is shown for the accurate collection and analysis of small quantities of CO₂ and CO, depending on CO₂ absorption and measurement of the residual volume of CO.  Where the gas mixture contains other constituents, a type of micro Orsat apparatus is used, containing, however, no rubber connections.  CO is not determined by absorption but is burned to CO₂ and then absorbed.  Unsaturated hydrocarbons are absorbed in fuming H₂SO₄, but the time of contact must be limited to 3-5 min. to prevent absorption of some CH₄ and H₂.  If CH₄ content is high, it is better to keep it below 40% by adding H₂, otherwise some of it will be converted into CH₃OH or CH₂O in the combustion pipet.  Details of the apparatus are shown in sketches.