| 摘要 |
<p>678,791. Gas analysers. BRITISH THOMSON-HOUSTON CO., Ltd. May 2, 1951 [May 17, 1950], No. 10297/51. Class 37. A glow discharge apparatus is arranged to detect a change in an otherwise stable atmospheric condition. A glass vessel 1 is provided with an inlet 2 and an outlet 3. The inlet 2 admits gases from the atmosphere through a needle valve 4 operated by a bellows 9. This is connected by a conduit 15 to the inlet 2 of the vessel 1, so that the pressure therein is maintained constant. The outlet 3 is connected to an exhausting apparatus 16 for producing a vacuum of about 2 or 3 cm. of mercury in the vessel 1. Filaments 19, 19a are sealed in the vessel 1 and are heated by batteries 20, 20a in series with regulating resistances 21, 21a. The heated filaments 19, 19a are connected in a circuit including a battery 22, ammeter 24, and a variable resistance 23. Change in the composition of the gas entering the vessel 1 is indicated by a change in the reading of the ammeter 24.</p> |
