Process and apparatus for the determination of the amount of carbonic acid contained in flue gases by the thermal conductivity method

摘要

279,478. Siemens & Halske Akt.-Ges. Oct. 25, 1926, [Convention date]. Gas analysis.-Relates to the process of testing flue gases by measuring the resistance of an electrically heated wire, past which they flow, a comparison wire in a current of air being also employed. It is stated that the reading of a bridge galvanometer employed in such a method varies with the voltage of the heating current, the rate of variation being proportional to the heating current when the wire is at 200‹ C. The test is therefore carried out at this temperature by means of the apparatus shown in the figure, the testing wires g, hand comparison wires n, o being enclosed in chambers through which flue gas and air pass respectively. The current is supplied from a transformer u which is connected to the test wires and the coil of a moving-coil galvanometer p as shown, and also to the field coils t of the galvanometer. The galvanometer is of the type fitted with a second moving coil short-circuited through a condenser. The Specification as open to inspection under Sect. 91 (3) (a), states that the variation of the galvanometer reading with the voltage is practically nil at 335‹, and that the tests may be carried out at this temperature with an ordinary galvanometer. This subject-matter does not appear in the Specification as accepted.